1.
Prefecture-level city
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Prefectural level cities form the second level of the administrative structure. Administrative chiefs of prefectural level cities generally have the rank as a division chief of a national ministry. Since the 1980s, most former prefectures have been renamed into prefectural level cities, a prefectural level city is a city and prefecture that have been merged into one unified jurisdiction. The larger prefectural level cities span over 100 kilometres, prefectural level cities nearly always contain multiple counties, county level cities, and other such sub-divisions. To distinguish a prefectural level city from its urban area. The first prefectural level cities were created on 5 November 1983, over the following two decades, prefectural level cities have come to replace the vast majority of Chinese prefectures, the process is still ongoing. Most provinces are composed entirely or nearly entirely of prefectural level cities, shijiazhuang and Zhengzhou are the largest prefectural level cities with populations approaching or exceeding some sub-provincial cities. A sub-prefecture-level city is a city with powers approaching those of prefectural level cities. There are total of three classification of prefecture-level city, Regular prefectural level city which consist of counties, county level cities, consolidated district-governed prefectural level city which only consist of districts as it subdivisions. Thus, Bloomington, Indiana is indicated on the map by a point, which is distinct from, and enclosed by, in China, however, large cities such as City of Xianning may, in reality, contain both urban and rural elements. Moreover, they may enclose counties or other cities, on a less detailed map, City of Xianning would be indicated by a point, more or less corresponding to the coordinates of its city government. Other populous areas may also be exhibited as points, such as County of Tongshan, with no indication that County of Tongshan is, in fact, enclosed by City of Xianning. On a more detailed map, City of Xianning would be drawn as an area, similar to a county of the United States and this convention may lead to difficulty in the identification of places mentioned in older sources. For example, Guo Moruo writes that he was born in Town of Shawan, within Prefecture of Leshan, and attended primary school in Town of Jiading. A modern map is unlikely to show either town, Shawan, because it is too small, and Jiading, because it is the seat of City of Leshan, and is therefore indicated on the map by a point labelled Leshan. A more detailed map would show Shawan as a district within City of Leshan, statistics of China such as population and industrial activity are generally reported along prefectural city lines. Thus, the relatively unknown City of Huangshi has 2.5 million residents, more than most European capitals, but upon closer inspection, furthermore, Huangshi contains several other cities, such as City of Daye. If a person wished to calculate the population of the area of Huangshi, and had a map of Huangshi, and a table of its population by district
2.
Yangxin County, Hubei
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Yangxin County is a county within the prefecture-level city of Huangshi in southeastern Hubei province, Peoples Republic of China. It occupies the half of the Huangshi City, bordering on Jiangxi in the south. The Yangtze River flows along the eastern border. The southern part of the county, located in the foothills of the Mufu Mountains, is hilly, according to the Fifth Population Census of China, the countys population was 949,100, making for the population density of 341 people per square kilometer. Besides the countys main urban area, other towns include Longgang. The county is rural, but more prosperous than its neighbor. The main transportation artery of the county is currently China National Highway 106, however, it does not pass through the Yangxin county seat, the town is served by Hubei provincial highway 316. The Yangxin Railway Station is located on the Wuhan–Jiujiang Railway, which runs from Wuhan to Jiujiang, a number of passenger trains running from the Wuchang stations in Wuhan stop at the Yangxin Railway Station. The distance from the Yangxin station to Wuchang by rail is 153 kilometres, the travel time by train being around 2 hours, usually with stops at the Huangshi station, Ezhou
3.
Geographic coordinate system
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A geographic coordinate system is a coordinate system used in geography that enables every location on Earth to be specified by a set of numbers, letters or symbols. The coordinates are chosen such that one of the numbers represents a vertical position. A common choice of coordinates is latitude, longitude and elevation, to specify a location on a two-dimensional map requires a map projection. The invention of a coordinate system is generally credited to Eratosthenes of Cyrene. Ptolemy credited him with the adoption of longitude and latitude. Ptolemys 2nd-century Geography used the prime meridian but measured latitude from the equator instead. Mathematical cartography resumed in Europe following Maximus Planudes recovery of Ptolemys text a little before 1300, in 1884, the United States hosted the International Meridian Conference, attended by representatives from twenty-five nations. Twenty-two of them agreed to adopt the longitude of the Royal Observatory in Greenwich, the Dominican Republic voted against the motion, while France and Brazil abstained. France adopted Greenwich Mean Time in place of local determinations by the Paris Observatory in 1911, the latitude of a point on Earths surface is the angle between the equatorial plane and the straight line that passes through that point and through the center of the Earth. Lines joining points of the same latitude trace circles on the surface of Earth called parallels, as they are parallel to the equator, the north pole is 90° N, the south pole is 90° S. The 0° parallel of latitude is designated the equator, the plane of all geographic coordinate systems. The equator divides the globe into Northern and Southern Hemispheres, the longitude of a point on Earths surface is the angle east or west of a reference meridian to another meridian that passes through that point. All meridians are halves of great ellipses, which converge at the north and south poles, the prime meridian determines the proper Eastern and Western Hemispheres, although maps often divide these hemispheres further west in order to keep the Old World on a single side. The antipodal meridian of Greenwich is both 180°W and 180°E, the combination of these two components specifies the position of any location on the surface of Earth, without consideration of altitude or depth. The grid formed by lines of latitude and longitude is known as a graticule, the origin/zero point of this system is located in the Gulf of Guinea about 625 km south of Tema, Ghana. To completely specify a location of a feature on, in, or above Earth. Earth is not a sphere, but a shape approximating a biaxial ellipsoid. It is nearly spherical, but has an equatorial bulge making the radius at the equator about 0. 3% larger than the radius measured through the poles, the shorter axis approximately coincides with the axis of rotation
4.
Provinces of China
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Provinces, formally provincial-level administrative divisions or first-level administrative divisions, are the highest-level Chinese administrative divisions. There are 34 such divisions, classified as 23 provinces, four municipalities, five autonomous regions, the Peoples Republic of China claims sovereignty over the territory administered by the Republic of China, claiming most of it as its Taiwan Province. The ROC also administers some offshore islands which form Fujian Province and these were part of an originally unified Fujian province, which since the stalemate of the Chinese Civil War in 1949 has been divided between the PRC and ROC. Note that every province has a Communist Party of China provincial committee, the committee secretary is in effective charge of the province, rather than the nominal governor of the provincial government. The government of each province is nominally led by a provincial committee. The committee secretary is first-in-charge of the province, second-in-command is the governor of the provincial government, the Peoples Republic of China claims the island of Taiwan and its surrounding islets, including Penghu, as Taiwan Province. The territory is controlled by the Republic of China, a municipality or direct-controlled municipality is a higher level of city which is directly under the Chinese government, with status equal to that of the provinces. In practice, their status is higher than that of common provinces. The governor of each region is usually appointed from the respective minority ethnic group. A special administrative region is an autonomous and self-governing subnational subject of the Peoples Republic of China that is directly under the Central Peoples Government. Each SAR has an executive as head of the region. The regions government is not fully independent, as policy and military defence are the responsibility of the central government. Notes,1, as of 20102, per km23, km24, Abbreviation in the parentheses is informal 5, Since founding in 1949, however, the PRC has never controlled Taiwan. Taiwan currently administers Taiwan, Penghu, Kinmen and Matsu, the subject of whether or not Taiwan is part of China is often debated, with no clear conclusion. The Ming Dynasty kept the system set up by the Yuan Dynasty, however. By the time of the establishment of the Qing Dynasty in 1644 there were 18 provinces, in addition, there was a zongdu, a general military inspector or governor general, for every two to three provinces. Outer regions of China were not divided into provinces, military leaders or generals oversaw Manchuria, Xinjiang, and Mongolia, while vice-dutong and civilian leaders headed the leagues, a subdivision of Mongolia. The ambans supervised the administration of Tibet, in 1884 Xinjiang became a province, in 1907 Fengtian, Jilin, and Heilongjiang were made provinces as well
5.
Hubei
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Hubei is a province of the Peoples Republic of China, located in the Central China region. The name of the province north of the lake, referring to its position north of Dongting Lake. The provincial capital is Wuhan, a major thoroughfare and the political, cultural. It borders Henan to the north, Anhui to the east, Jiangxi to the southeast, Hunan to the south, Chongqing to the west, the high-profile Three Gorges Dam is located at Yichang, in the west of the province. The Hubei region was home to sophisticated Neolithic cultures, by the Spring and Autumn period, the territory of todays Hubei was part of the powerful State of Chu. During the Warring States period Chu became the major adversary of the upstart State of Qin to the northwest, which began to assert itself by outward expansionism. As wars between Qin and Chu ensued, Chu lost more and more land, first its dominance over the Sichuan Basin, then its heartland, which correspond to modern Hubei. In 223 BC Qin chased down the remnants of the Chu regime, Qin founded the Qin dynasty in 221 BC, the first unified state in the region. Qin was succeeded by the Han dynasty in 206 BC, which established the province of Jingzhou in what is now Hubei, the Qin and Han played an active role in the agricultural colonization of Hubei, maintaining a system of river dikes to protect farmland from summer floods. Towards the end of the Han Dynasty in the beginning of the 3rd century, the incursion of northern nomadic peoples into the region at the beginning of the 4th century began nearly three centuries of division into a nomad-ruled north and a Han Chinese-ruled south. Hubei, to the South, remained under southern rule for this entire period, until the unification of China by the Sui dynasty in 589. After the Tang dynasty disintegrated in the 10th century, Hubei came under the control of several regional regimes, Jingnan in the center, Wu to the east, and the Five Dynasties to the north. The Song dynasty reunified the region in 982 and placed most of Hubei into Jinghubei Circuit, Mongols conquered the region in 1279, and under their rule the province of Huguang was established, covering Hubei, Hunan, and parts of Guangdong and Guangxi. The Ming dynasty drove out the Mongols in 1368 and their version of Huguang province was smaller, and corresponded almost entirely to the modern provinces of Hubei and Hunan combined. While Hubei was geographically removed from the centers of the Ming power, during the last years of the Ming, todays Hubei was ravaged several times by the rebel armies of Zhang Xianzhong and Li Zicheng. The Manchu Qing dynasty which had much of the region in 1644, soon split Huguang into the provinces of Hubei. The Huangshi/Daye area, south-east of Wuhan, became an important center of mining, in 1911 the Wuchang Uprising took place in modern-day Wuhan, overthrowing the Qing dynasty and establishing the Republic of China. In 1927 Wuhan became the seat of a government established by left-wing elements of the Kuomintang, led by Wang Jingwei, during World War II the eastern parts of Hubei were conquered and occupied by Japan while the western parts remained under Chinese control
6.
Metropolitan area
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As social, economic and political institutions have changed, metropolitan areas have become key economic and political regions. The Greater São Paulo is a term for one of the multiple definitions the large metropolitan area located in the São Paulo state in Brazil. A metropolitan area combines an urban agglomeration with zones not necessarily urban in character and these outlying zones are sometimes known as a commuter belt, and may extend well beyond the urban zone, to other political entities. For example, El Monte, California is considered part of the Los Angeles metro area in the United States, in practice, the parameters of metropolitan areas, in both official and unofficial usage, are not consistent. Population figures given for one area can vary by millions. A polycentric metropolitan area is one not connected by continuous development or conurbation, in defining a metropolitan area, it is sufficient that a city or cities form a nucleus that other areas have a high degree of integration with. The Australian Bureau of Statistics defines statistical divisions as areas under the influence of one or more major towns or a major city. However, this definition has become obsolete with the conurbation of several statistical divisions into a larger metropolitan areas. In Brazil, metropolitan areas are called metropolitan regions, each State defines its own legislation for the creation, definition and organization of a metropolitan region. The creation of a region is not intended for any statistical purpose, although the Brazilian Institute of Geography. Their main purpose is to allow for a management of public policies of common interest to all cities involved. They dont have political, electoral or jurisdictional power whatsoever, so living in a metropolitan region do not elect representatives for them. Statistics Canada defines a metropolitan area as an area consisting of one or more adjacent municipalities situated around a major urban core. To form a CMA, the area must have a population of at least 100,000. To be included in the CMA, adjacent municipalities must have a degree of integration with the core. As of the Canada 2011 Census, there were 33 CMAs in Canada, including six with a population over one million—Toronto, Montreal, Vancouver, Ottawa, Calgary and Edmonton. In Denmark the only area is Greater Copenhagen, consisting of the Capital Region of Denmark along with the neighboring regions Region Zealand. Greater Copenhagen has an population of 1.25 million people
7.
Time in China
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The time in China follows a single standard time offset of UTC+08,00, despite China spanning five geographical time zones. The official national standard time is called Beijing Time domestically and China Standard Time internationally, daylight saving time has not been observed since 1991. The special administrative regions maintain their own authorities, with standards called Hong Kong Time. These have been equivalent to Beijing time since 1992, in addition, a second time standard is used in Xinjiang, two hours less than the Beijing Time, which is called Ürümqi Time or Xinjiang Time. In 1912, the Republic of China established five standard time zones, namely Kunlun, Sinkiang-Tibet, Kansu-Szechwan, Chungyuan, and Changpai. The unified time zone policy was adopted by the Communist Party of China or the Central People’s Government some time between 27 September 1949 and 6 October 1949, the date is unknown. However, recent research suggests that the policy was most likely adopted on 27 September 1949, daylight saving time was observed from 1986 to 1991. In 1997 and 1999, Hong Kong and Macau were transferred to China from the United Kingdom and Portugal, although the sovereignty of the SARs belongs to China, they retain their own policies regarding time zones for historical reasons. Due to their locations, both are within the UTC+08,00 time zone, which is the same as the national standard — Beijing time. Xinjiang Time, also known as Ürümqi Time, is set due to its location in the westernmost part of the country. The time offset is UTC+06,00, which is two hours behind Beijing, and is shared with neighbouring Kazakhstan and Kyrgyzstan. Currently, timezone usage within Xinjiang is roughly split along the divide, with most ethnic Han following Beijing time. Some local authorities are now using both time standard side by side, the coexistence of two timezones within the same region causes some confusion among the local population, especially when inter-racial communication occur. Some ethnic Han in Xinjiang might not be aware of the existence of the UTC+6 Xinjiang Time because of language barrier, regardless, Beijing Time users in Xinjiang usually schedule their daily activities two hours later than those who live in eastern China. As such, stores and offices in Xinjiang are commonly opening from 10am to 7pm Beijing Time and this is known as the work/rest time in Xinjiang. Hong Kong maintains its own time authority after transfer of sovereignty in 1997, the Hong Kong Time is UTC+08,00 all year round, and daylight saving time has not been used since 1979. Greenwich Mean Time was adopted as the basis in 1904, before that, local time was determined by astronomical observations at Hong Kong Observatory using a 6-inch Lee Equatorial and a 3-inch Transit Circle. Macau maintains its own time authority after transfer of sovereignty in 1999, the Macau Standard Time is the time in Macau
8.
Vehicle registration plates of China
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China, officially the Peoples Republic of China issues vehicles licence plates at its Vehicle Management Offices, under the administration of the Ministry of Public Security. Hong Kong and Macau have their own administrations on licence plates, Vehicles from Hong Kong and Macau are required to apply for licence plates, usually from Guangdong, to travel on roads in Mainland China. Vehicles from Mainland China have to apply for Hong Kong or Macau licence plates to enter those territories, taiwan, on the other hand, also has plates administered by the Ministry of Transportation and Communications in the Republic of China. The number of registered cars, buses, vans, and trucks on the road in China reached 62 million in 2009, and is expected to exceed 200 million by 2020. The font used on the plates were said to be modified from the East Asian gothic typeface, the current plates are of the 1992 standard, which consist of the one-character provincial abbreviation, a letter of the alphabet, and five numbers or letters of the alphabet. Previously, all plates had used the five-number designation. As the number of motor vehicles grew, however, the number had to exceed what was the maximum previously allowable—90,000 or 100,000 vehicles, therefore, there had become a need to insert Latin letters into the license plate to increase the number of possible combinations. This was first done in the cities with only one prefix. Nanjing, for example, began the change only the first number. Further changes allowed the first two places, or the place alone on the plate to be letters, allowing 792,000 more combinations mathematically. More recently, cities have taken to having the letter alone being a Latin letter. The numbers are produced at random, and are computer-generated at the issuing office, numbers with a sequence of 6s, 8s, or 9s are usually considered to be lucky, therefore special sequences like 88888 or 86888 can be purchased. The older black plates are issued to those who are dual-use vehicles. Licence plates for Chinas Police Service, Armed Police Force, and Military are in a background, with red. Police Service plates have a format of X·LLNNN警. These plates are issued to police, some patrol vehicles, court. Chinese Peoples Armed Police Force uses the pinyin wujing abbreviation WJ, the first two small letters behind the WJ are area prefixes, WJ01-NNNNN. = Hainan The Alphabet Numeral behind the area shows the section of the Armed police
9.
Simplified Chinese characters
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Simplified Chinese characters are standardized Chinese characters prescribed in the Table of General Standard Chinese Characters for use in mainland China. Along with traditional Chinese characters, it is one of the two character sets of the contemporary Chinese written language. The government of the Peoples Republic of China in mainland China has promoted them for use in printing since the 1950s and 1960s in an attempt to increase literacy and they are officially used in the Peoples Republic of China and Singapore. Traditional Chinese characters are used in Hong Kong, Macau. Overseas Chinese communities generally tend to use traditional characters, Simplified Chinese characters may be referred to by their official name above or colloquially. Strictly, the latter refers to simplifications of character structure or body, character forms that have existed for thousands of years alongside regular, Simplified character forms were created by decreasing the number of strokes and simplifying the forms of a sizable proportion of traditional Chinese characters. Some simplifications were based on popular cursive forms embodying graphic or phonetic simplifications of the traditional forms, some characters were simplified by applying regular rules, for example, by replacing all occurrences of a certain component with a simplified version of the component. Variant characters with the pronunciation and identical meaning were reduced to a single standardized character. Finally, many characters were left untouched by simplification, and are identical between the traditional and simplified Chinese orthographies. Some simplified characters are very dissimilar to and unpredictably different from traditional characters and this often leads opponents not well-versed in the method of simplification to conclude that the overall process of character simplification is also arbitrary. In reality, the methods and rules of simplification are few, on the other hand, proponents of simplification often flaunt a few choice simplified characters as ingenious inventions, when in fact these have existed for hundreds of years as ancient variants. However, the Chinese government never officially dropped its goal of further simplification in the future, in August 2009, the PRC began collecting public comments for a modified list of simplified characters. The new Table of General Standard Chinese Characters consisting of 8,105 characters was promulgated by the State Council of the Peoples Republic of China on June 5,2013, cursive written text almost always includes character simplification. Simplified forms used in print have always existed, they date back to as early as the Qin dynasty, One of the earliest proponents of character simplification was Lubi Kui, who proposed in 1909 that simplified characters should be used in education. In the years following the May Fourth Movement in 1919, many anti-imperialist Chinese intellectuals sought ways to modernise China, Traditional culture and values such as Confucianism were challenged. Soon, people in the Movement started to cite the traditional Chinese writing system as an obstacle in modernising China and it was suggested that the Chinese writing system should be either simplified or completely abolished. Fu Sinian, a leader of the May Fourth Movement, called Chinese characters the writing of ox-demons, lu Xun, a renowned Chinese author in the 20th century, stated that, If Chinese characters are not destroyed, then China will die. Recent commentators have claimed that Chinese characters were blamed for the problems in China during that time
10.
Traditional Chinese characters
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Traditional Chinese characters are Chinese characters in any character set that does not contain newly created characters or character substitutions performed after 1946. They are most commonly the characters in the character sets of Taiwan, of Hong Kong. Currently, a number of overseas Chinese online newspapers allow users to switch between both sets. In contrast, simplified Chinese characters are used in mainland China, Singapore, the debate on traditional and simplified Chinese characters has been a long-running issue among Chinese communities. Although simplified characters are taught and endorsed by the government of Mainland China, Traditional characters are used informally in regions in China primarily in handwriting and also used for inscriptions and religious text. They are often retained in logos or graphics to evoke yesteryear, nonetheless, the vast majority of media and communications in China is dominated by simplified characters. Taiwan has never adopted Simplified Chinese characters since it is ruled by the Republic of China, the use of simplified characters in official documents is even prohibited by the government in Taiwan. Simplified characters are not well understood in general, although some stroke simplifications that have incorporated into Simplified Chinese are in common use in handwriting. For example, while the name of Taiwan is written as 臺灣, similarly, in Hong Kong and Macau, Traditional Chinese has been the legal written form since colonial times. In recent years, because of the influx of mainland Chinese tourists, today, even government websites use simplified Chinese, as they answer to the Beijing government. This has led to concerns by residents to protect their local heritage. In Southeast Asia, the Chinese Filipino community continues to be one of the most conservative regarding simplification, while major public universities are teaching simplified characters, many well-established Chinese schools still use traditional characters. Publications like the Chinese Commercial News, World News, and United Daily News still use traditional characters, on the other hand, the Philippine Chinese Daily uses simplified. Aside from local newspapers, magazines from Hong Kong, such as the Yazhou Zhoukan, are found in some bookstores. In case of film or television subtitles on DVD, the Chinese dub that is used in Philippines is the same as the one used in Taiwan and this is because the DVDs belongs to DVD Region Code 3. Hence, most of the subtitles are in Traditional Characters, overseas Chinese in the United States have long used traditional characters. A major influx of Chinese immigrants to the United States occurred during the half of the 19th century. Therefore, the majority of Chinese language signage in the United States, including street signs, Traditional Chinese characters are called several different names within the Chinese-speaking world
11.
Pinyin
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Pinyin, or Hànyǔ Pīnyīn, is the official romanization system for Standard Chinese in mainland China, Malaysia, Singapore, and Taiwan. It is often used to teach Standard Chinese, which is written using Chinese characters. The system includes four diacritics denoting tones, Pinyin without tone marks is used to spell Chinese names and words in languages written with the Latin alphabet, and also in certain computer input methods to enter Chinese characters. The pinyin system was developed in the 1950s by many linguists, including Zhou Youguang and it was published by the Chinese government in 1958 and revised several times. The International Organization for Standardization adopted pinyin as a standard in 1982. The system was adopted as the standard in Taiwan in 2009. The word Hànyǔ means the language of the Han people. In 1605, the Jesuit missionary Matteo Ricci published Xizi Qiji in Beijing and this was the first book to use the Roman alphabet to write the Chinese language. Twenty years later, another Jesuit in China, Nicolas Trigault, neither book had much immediate impact on the way in which Chinese thought about their writing system, and the romanizations they described were intended more for Westerners than for the Chinese. One of the earliest Chinese thinkers to relate Western alphabets to Chinese was late Ming to early Qing Dynasty scholar-official, the first late Qing reformer to propose that China adopt a system of spelling was Song Shu. A student of the great scholars Yu Yue and Zhang Taiyan, Song had been to Japan and observed the effect of the kana syllabaries. This galvanized him into activity on a number of fronts, one of the most important being reform of the script, while Song did not himself actually create a system for spelling Sinitic languages, his discussion proved fertile and led to a proliferation of schemes for phonetic scripts. The Wade–Giles system was produced by Thomas Wade in 1859, and it was popular and used in English-language publications outside China until 1979. This Sin Wenz or New Writing was much more sophisticated than earlier alphabets. In 1940, several members attended a Border Region Sin Wenz Society convention. Mao Zedong and Zhu De, head of the army, both contributed their calligraphy for the masthead of the Sin Wenz Societys new journal. Outside the CCP, other prominent supporters included Sun Yat-sens son, Sun Fo, Cai Yuanpei, the countrys most prestigious educator, Tao Xingzhi, an educational reformer. Over thirty journals soon appeared written in Sin Wenz, plus large numbers of translations, biographies, some contemporary Chinese literature, and a spectrum of textbooks
12.
Daye
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Daye is a city of eastern Hubei province, Peoples Republic of China. Administratively, it is a city of Huangshi City. Before the adoption of the Hanyu Pinyin, the name of the city was often transcribed in English as Tayeh. As it is usually the case with county-level cities, Daye includes both a core and a fair amount of rural land in all directions, with smaller townships such as Dajipu. According to the Fifth Population Census of China, the entire city of Daye had 813,600 residents. The Daye Lake south of Dayes urban core is surrounded by parks and fishing ponds, for a traveler who goes on G316 from Wuhan toward the south-east, Daye appears as a border between the more urban and more rural parts of the province. Daye sits on the border of the heavily industrialized Wuhan/Ezhou/Huangshi metropolitan area, south of it. Daye is a city, a center of mining and metallurgy. According to archaeologists, copper mining and smelting was conducted at Dayes Tonglüshan Mine as early as the Spring and Autumn period, Tonglüshan Mine is located just southwest of the modern city, and now has a museum. Among the major employers is Huangshi Daye Non-ferrous Metals Co. Ltd, Daye was the junction of the Wuhan-Daye Railway and Daye-Shahejie Railway, which merged in 1989 to form the Wuhan–Jiujiang Railway. Huangshi Railway Station, which is the passenger station for the entire Huangshi metropolitan area, is located within Dayes administrative borders. It has fairly frequent service, with time to Wuhan being typically around 1 hour on a high-speed D-series train. Daye is served by the Wuhan–Huangshi Intercity Railway, part of the future Wuhan Metropolitan Area Intercity Railway, the new Daye North Railway Station, located north-east of Dayes main urban area, serves as that lines terminal. It has fairly frequent service to the Wuhan Railway Station, construction work is carried out to extent this rail line beyond Daye, this will become the Wuhan–Jiujiang Passenger Railway. Daye is also served by the China National Highway 106, Daye County existed on and off for centuries, as recently as the World War II period, it included much of todays prefecture-level city of Huangshi. This means that pre-1949 references to a location in Daye or Tayeh may refer to anywhere within todays Huangshi, Daye County was re-established on June 1,1962, on a rather smaller scale, as part of Huangshi City. On February 18,1994 Daye was converted into a county-level city, the speech of Daye and the adjacent counties farther south has been traditionally characterized as the Daye dialect, part of the Datong dialect group of Gan Chinese
13.
Aerial engagements of the Second Sino-Japanese War
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The Second Sino-Japanese War began on 7 July 1937 with the Marco Polo Bridge Incident in the Republic of China. The regional conflict lasted until the end of World War II, by the end of July 1937, fighting had escalated into a full-scale war and both countries deployed their air forces, ground troops, and warships into combat. Japanese heavy bombers also extensively bombed Chinese factories, airfields and conducted the first major air-raids against civilian targets in the war. At the outset of war, China primarily relied on foreign countries for its military aircraft and these volunteers included future ace-fighter pilots Art Chin and John Wong. Both the Soviet Union and the United States came to Chinas aid by supplying aircraft, at the outbreak of the Sino-Japanese War/War of Resistance/WWII in July 1937, the Chinese Air Force had 645 combat aircraft, of which about 300 were fighter planes. Japan had 1,530 army and navy aircraft, of which about 400 were deployed in China, most of the Chinese combat aircraft were U. S. models, and the Chinese pilots were mostly trained by American or American-trained aviators.32. In August 1937 Claire Lee Chennault accepted the offer to become air adviser to Chiang Kai-shek, on 14 August 1937 the Chinese Air Force fighter squadrons sortied for the defense of Shanghai and Nanjing, capital of the Republic of China. Kao attacked a G3M bomber and scored a direct hit sending it plummeting to the ground in flames, meanwhile, three other Hawk IIIs attacked a third G3M bomber and shot it down. The second group of Japanese G3M bombers attacking Guangde Airfield was intercepted by the 22nd Squadron of the 4th Pursuit Group and the 34th Squadron. Squadron Commander Cheng Hsiao-yu of the 22nd Squadron shot up the right engine, in addition, two G3Ms were also shot down by ground anti-aircraft fire. On the following day at dawn 15 August,12 Japanese Type 89 torpedo bombers were intercepted over Hangzhou by 21 Hawk IIIs of the Chinese 4th Pursuit Group led by Group Commander Kao Chi-hang, the Chinese shot down eight bombers. The Chinese shot down four and damaged six Japanese G3M bombers, on 16 August, the Japanese launched two raids with a total of 11 Japanese G3M bombers on the airfield near Nanjing, they were intercepted by five Chinese fighters from the 17th and 28th Squadrons. The Chinese shot down three Japanese bombers, and lost three fighters, on 17 August Chinese Hawk III fighters flew 17 sorties shooting down one Japanese bomber, the Chinese lost two aircraft. In that period the Chinese shot down 24 Japanese planes and lost 11 aircraft, the Chinese Air Force pilots fought well despite their airfields being under constant Japanese air attacks. Some of the planes were flown by Soviet volunteer military pilots sent to China, aircraft provided by the Soviet Union included Tupolev SB twin-engine and Tupolev TB-3 4-engine bombers, and their latest Polikarpov I-15 biplane fighters and Polikarpov I-16 monoplane fighters. According to Soviet records, by the beginning of September 1938, China received from the Soviet Union 361 aircraft, of which 238 were I-15, together with the American and other foreign planes, the Chinese Air Force had a total of 602 aircraft. By the beginning of 1939, according to Chinese information, the Chinese Air Force had less than 100 aircraft of various types, a new group of 30 Soviet I-15s arrived in Lanzhou on 18 July, while 30 Soviet I-16s arrived on 3 August 1939. From mid-1938 to mid-1939, Japanese forces intensified their attacks on the front near Lanzhou, the Japanese air units were operating from airfields in Shanxi at the margin of the operating range of their fighters, and their bombers were often not escorted by fighter planes
14.
Yangtze
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The Yangtze River, known in China as the Cháng Jiāng or the Yángzǐ Jiāng, is the longest river in Asia and the third-longest in the world. The river is the longest in the world to flow entirely within one country and it drains one-fifth of the land area of the Peoples Republic of China and its river basin is home to one-third of the countrys population. The Yangtze is the sixth-largest river by volume in the world. The Yangtze River plays a role in the history, culture. The prosperous Yangtze River Delta generates as much as 20% of the PRCs GDP, for thousands of years, the river has been used for water, irrigation, sanitation, transportation, industry, boundary-marking and war. The Three Gorges Dam on the Yangtze River is the largest hydro-electric power station in the world, in recent years, the river has suffered from industrial pollution, agricultural run-off, siltation, and loss of wetland and lakes, which exacerbates seasonal flooding. Some sections of the river are now protected as nature reserves, a stretch of the upstream Yangtze flowing through deep gorges in western Yunnan is part of the Three Parallel Rivers of Yunnan Protected Areas, a UNESCO World Heritage Site. In mid-2014 the Chinese government announced it was building a transport network, comprising railways, roads and airports. Because the source of the Yangtze was not ascertained until modern times, Yangtze was actually the name of Chang Jiang for the lower part from Nanjing to the river mouth at Shanghai. In modern Chinese, Yangtze is still used to refer to the part of Chang Jiang from Nanjing to the river mouth. Yangtze never stands for the whole Chang Jiang, Chang Jiang is the modern Chinese name for the lower 2,884 km of the Yangtze from its confluence with the Min River at Yibin in Sichuan Province to the river mouth at Shanghai. Chang Jiang literally means the Long River, in Old Chinese, this stretch of the Yangtze was simply called Jiang/Kiang 江, a character of phono-semantic compound origin, combining the water radical 氵 with the homophone 工. Krong was probably a word in the Austroasiatic language of local peoples such as the Yue, similar to *krong in Proto-Vietnamese and krung in Mon, all meaning river, it is related to modern Vietnamese sông and Khmer kôngkea. By the Han Dynasty, Jiang had come to any river in Chinese. The epithet 長, means long, was first formally applied to the river during the Six Dynasties period, various sections of Chang Jiang have local names. From Yibin to Yichang, the river through Sichuan and Chongqing Municipality is also known as the Chuan Jiang or Sichuan River, in the Hubei Province, the river is also called the Jing Jiang or the Jing River after Jingzhou. In Anhui Province, the takes on the local name Wan Jiang after the shorthand name for Anhui. And Yangzi Jiang t 揚子江s 扬子江, p Yángzǐjiāng) or the Yangzi River, the name likely comes from an ancient ferry crossing called Yangzi or Yangzijin
15.
Jiangxi
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Jiangxi is a province in the Peoples Republic of China, located in the southeast of the country. The name Jiangxi derives from the circuit administrated under the Tang dynasty in 733, the short name for Jiangxi is 赣, for the Gan River which runs across from the south to the north and flows into the Yangtze River. Jiangxi is also alternately called Ganpo Dadi which literally means the Great Land of Gan, Jiangxi is centered on the Gan River valley, which historically provided the main north-south transport route of south China. The corridor along the Gan River is one of the few easily traveled routes through the otherwise mountainous, as a result, Jiangxi has been strategically important throughout much of Chinas history. Jiangxi was outside the sphere of influence of early Chinese civilization during the Shang dynasty and it is likely that peoples collectively known as the Baiyue inhabited the region. During the Spring and Autumn period, the part of modern Jiangxi formed the western frontier of the state of Wu. After Wu was conquered by the state of Yue in 473 BC, Chu subjugated Yue in 333 BC. In 223 BC, when Qin conquered Chu, majority of Jiangxi area was recorded to be put under Jiujiang Commandary situated in Shouchun, however the commandary was ineffective and ended shortly when Qin falls. It was named after the Yuzhang River, the name of Gan River. Gan has become the abbreviation of the province, in 201, eight counties were added to the original seven of Qin, and three more were established in later years. Throughout most of the Han dynasty the commanderys eighteen counties covered most of the province of Jiangxi. The county seats of Nanchang, Gan, Yudu, Luling among others were located at the sites of major cities. Other counties, however, have moved or abolished in later centuries. Under the reign of Emperor Wu of the Han dynasty, Yuzhang Commandery was assigned to Yangzhou Province, in 291 AD, during the Western Jin dynasty, Jiangxi became its own Zhou called Jiangzhou. During the Southern and Northern Dynasties, Jiangxi was under the control of the dynasties. During the Sui dynasty, there were seven commanderies and twenty-four counties in Jiangxi, during the Tang dynasty, another commandery and fourteen counties were added. Commanderies were then abolished, becoming zhou, circuits were established during the Tang dynasty as a new top-level administrative division. At first Jiangxi was part of the Jiangnan Circuit, in 733, this circuit was divided into western and eastern halves
16.
District (China)
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The term district, in the context of China, is used to refer to several unrelated political divisions in both ancient and modern China. In the modern context, district or sub-city, formally city-governed district, city-controlled district, the rank of a district derives from the rank of its city. Districts of a municipality are prefecture-level, districts of a city are sub-prefecture-level. It was also used to refer the obsolete County-controlled districts. However, if the district is encountered in the context of ancient Chinese history, then it is a translation for xian. As a result, districts were also mostly urban or suburban in nature, after the 1980s, prefectures began to be replaced with prefecture-level cities. From then on, cities in mainland China became just like any other division, containing urban areas, towns, villages. These cities are subdivided into districts, counties, autonomous counties, at the same time, counties and county-level cities began to be replaced with districts, especially after 1990. From then onwards, districts were no longer strictly an urban entities — some districts today are just like counties, with a large towns, a regular district under a municipality or prefecture-level city. A type of city districts that are created for ethnic minorities. Currently there are 4 such ethnic districts, three in Henan and one in Heilongjiang, chanhe Hui District Guancheng Hui District Shunhe Hui District Meilisi Daur District Huimin District A special county-level division located in Guizhou. Liuzhi Special District, Liupanshui A special Sub-prefectural-level forestry district located in Hubei, shennongjia A county-controlled district sometimes translated as county-governed district, county district or sub-county, is a sub-county in the Peoples Republic of China. A branch of a county government, a public office is the administrative office in a district. A county-controlled district was once an important subdivision of a county all over China from 1950s to 1990s and it was common for there to be about 5 to 10 districts in a county, then about 3 to 5 towns and townships in a district. After the 1990s, county-controlled districts began to be phased out, if the word district is encountered in the context of ancient Chinese history, then the word is a translation for xian, another type of administrative division in China. Xian has been translated using several English terms, in the context of ancient history, district and prefecture are commonly used, while county is used for more contemporary contexts. See Counties of the Peoples Republic of China for more information on the xian of China, list of districts in China District
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Counties of the People's Republic of China
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There are 1,464 counties in Mainland China out of a total of 2,862 county-level divisions. Xian have existed since the Warring States period, and were established nationwide during the Qin Dynasty, the term xian is usually translated as districts or prefectures when put in the context of Chinese history. This article, however, will try to keep the terminology consistent with the modern translation, xian have existed since the Warring States period and were set up nationwide by the Qin Dynasty. The number of counties in China proper gradually increased from dynasty to dynasty, as Qin Shi Huang reorganized the counties after his unification, there were about 1,000. Under the Eastern Han Dynasty, the number of counties increased to above 1,000, about 1400 existed when the Sui dynasty abolished the commandery level, which was the level just above counties, and demoted some commanderies to counties. The current number of counties mostly resembled that of the years of Qing Dynasty. Changes of location and names of counties in Chinese history have been a field of research in Chinese historical geography. Government below the county level was often undertaken through informal non-bureaucratic means, the head of a county was the magistrate, who oversaw both the day-to-day operations of the county as well as civil and criminal cases. Autonomous counties are a class of counties in Mainland China reserved for non-Han Chinese ethnic minorities. Autonomous counties are all over China, and are given, by law. There are 117 autonomous counties in Mainland China, as the Communist Party of China is central to directing government policy in Mainland China, every level of administrative division has a local CPC Committee. A countys is called the CPC County Committee and the called the Secretary. Policies are carried out via the Peoples government of the county, the governor is often also one of the deputy secretaries in the CPC Committee. County List of counties in the Peoples Republic of China List of county-level divisions of China History of the divisions of China
18.
County-level city
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A county-level municipality, county-level city, or county city is a county-level administrative division of mainland China. County-level cities are governed by prefecture-level divisions, but a few are governed directly by province-level divisions. Most county-level cities were created in the 1980s and 1990s by replacing counties, a county-level city is a city and county that have been merged into one unified jurisdiction. As such it is simultaneously a city, which is an entity. County-level cities are not cities in the strictest sense of the word, since they usually contain rural areas many times the size of their urban and this is because the counties that county-level cities have replaced are themselves large administrative units containing towns, villages, and farmland. To distinguish a city from its actual urban area, the term 市区 shìqū. In France, an equivalent of a city is an agglomeration community. For example, in New South Wales such a unit may often be called a city, city of Blue Mountains is made of a number of towns. Another example would be municipal government in the Canadian province of Ontario and this agglomeration includes all of the townships in the county of Kent, with cities and towns like Wallaceberg, Thamesville, Dresden, Wheatley. This amalgamation as it is referred to, was controversial when it was forced upon the constituents through provincial legislation. Today, instead of each city having its own mayor and city councillors, as of January 2017, there are 360 County-level city in total, A sub-prefecture-level city is a county-level city with powers approaching those of prefecture-level cities. Examples include, Xiantao, Qianjiang, Tianmen and Jiyuan, administrative divisions of China Counties of the Peoples Republic of China Prefecture-level city List of cities in China
19.
Standard Chinese
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Its pronunciation is based on the Beijing dialect, its vocabulary on the Mandarin dialects, and its grammar is based on written vernacular Chinese. Like other varieties of Chinese, Standard Chinese is a language with topic-prominent organization. It has more initial consonants but fewer vowels, final consonants, Standard Chinese is an analytic language, though with many compound words. There exist two standardised forms of the language, namely Putonghua in Mainland China and Guoyu in Taiwan, aside from a number of differences in pronunciation and vocabulary, Putonghua is written using simplified Chinese characters, while Guoyu is written using traditional Chinese characters. There are many characters that are identical between the two systems, in English, the governments of China and Hong Kong use Putonghua, Putonghua Chinese, Mandarin Chinese, and Mandarin, while those of Taiwan, Singapore, and Malaysia, use Mandarin. The name Putonghua also has a long, albeit unofficial, history and it was used as early as 1906 in writings by Zhu Wenxiong to differentiate a modern, standard Chinese from classical Chinese and other varieties of Chinese. For some linguists of the early 20th century, the Putonghua, or common tongue/speech, was different from the Guoyu. The former was a prestige variety, while the latter was the legal standard. Based on common understandings of the time, the two were, in fact, different, Guoyu was understood as formal vernacular Chinese, which is close to classical Chinese. By contrast, Putonghua was called the speech of the modern man. The use of the term Putonghua by left-leaning intellectuals such as Qu Qiubai, prior to this, the government used both terms interchangeably. In Taiwan, Guoyu continues to be the term for Standard Chinese. The term Putonghua, on the contrary, implies nothing more than the notion of a lingua franca, Huayu, or language of the Chinese nation, originally simply meant Chinese language, and was used in overseas communities to contrast Chinese with foreign languages. Over time, the desire to standardise the variety of Chinese spoken in these communities led to the adoption of the name Huayu to refer to Mandarin and it also incorporates the notion that Mandarin is usually not the national or common language of the areas in which overseas Chinese live. The term Mandarin is a translation of Guānhuà, which referred to the lingua franca of the late Chinese empire, in English, Mandarin may refer to the standard language, the dialect group as a whole, or to historic forms such as the late Imperial lingua franca. The name Modern Standard Mandarin is sometimes used by linguists who wish to distinguish the current state of the language from other northern. Chinese has long had considerable variation, hence prestige dialects have always existed. Confucius, for example, used yǎyán rather than colloquial regional dialects, rime books, which were written since the Northern and Southern dynasties, may also have reflected one or more systems of standard pronunciation during those times
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Chinese language
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Chinese is a group of related, but in many cases mutually unintelligible, language varieties, forming a branch of the Sino-Tibetan language family. Chinese is spoken by the Han majority and many ethnic groups in China. Nearly 1.2 billion people speak some form of Chinese as their first language, the varieties of Chinese are usually described by native speakers as dialects of a single Chinese language, but linguists note that they are as diverse as a language family. The internal diversity of Chinese has been likened to that of the Romance languages, There are between 7 and 13 main regional groups of Chinese, of which the most spoken by far is Mandarin, followed by Wu, Min, and Yue. Most of these groups are mutually unintelligible, although some, like Xiang and certain Southwest Mandarin dialects, may share common terms, all varieties of Chinese are tonal and analytic. Standard Chinese is a form of spoken Chinese based on the Beijing dialect of Mandarin. It is the language of China and Taiwan, as well as one of four official languages of Singapore. It is one of the six languages of the United Nations. The written form of the language, based on the logograms known as Chinese characters, is shared by literate speakers of otherwise unintelligible dialects. Of the other varieties of Chinese, Cantonese is the spoken language and official in Hong Kong and Macau. It is also influential in Guangdong province and much of Guangxi, dialects of Southern Min, part of the Min group, are widely spoken in southern Fujian, with notable variants also spoken in neighboring Taiwan and in Southeast Asia. Hakka also has a diaspora in Taiwan and southeast Asia. Shanghainese and other Wu varieties are prominent in the lower Yangtze region of eastern China, Chinese can be traced back to a hypothetical Sino-Tibetan proto-language. The first written records appeared over 3,000 years ago during the Shang dynasty, as the language evolved over this period, the various local varieties became mutually unintelligible. In reaction, central governments have sought to promulgate a unified standard. Difficulties have included the great diversity of the languages, the lack of inflection in many of them, in addition, many of the smaller languages are spoken in mountainous areas that are difficult to reach, and are often also sensitive border zones. Without a secure reconstruction of proto-Sino-Tibetan, the structure of the family remains unclear. A top-level branching into Chinese and Tibeto-Burman languages is often assumed, the earliest examples of Chinese are divinatory inscriptions on oracle bones from around 1250 BCE in the late Shang dynasty
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Han Chinese
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The Han Chinese, Han people or simply Han are an ethnic group native to East Asia. They constitute approximately 92% of the population of China, 95% of Taiwan, 76% of Singapore, 23% of Malaysia, Han Chinese are the worlds largest ethnic group with over 1.3 billion people. Similarly, the Chinese language also came to be named the Han language ever since, in the Oxford Dictionary, the Han are defined as The dominant ethnic group in China. In the Encyclopedia of the Peoples of Asia and Oceania, the Han are called the dominant population in China, as well as in Taiwan, according to the Merriam-Webster Dictionary, the Han are the Chinese peoples especially as distinguished from non-Chinese elements in the population. The name Hanzhong, in turn, was derived from the Han River, which flows through the regions plains. The river, in turn, derives its name from such as Tianhan, Yinhan, Xinghan or Yunhan, all ancient Chinese poetic nicknames for the Milky Way. This gave rise to a commonly used nowadays by overseas Chinese for ethnic identity – Huaren. The term is used in conversation and is also an element in the Cantonese word for Chinatown. The vast majority of Han Chinese – over 1.2 billion of them – live in areas under the jurisdiction of the Peoples Republic of China, where they constitute about 92% of its population. Han Chinese also constitute the majority in both of the administrative regions of the PRC—about 95% and 96% of the population of Hong Kong and Macau. There are over 22 million Han Chinese in Taiwan, they began migrating from the coastal provinces of mainland China to Taiwan during the 13th to 17th century. At first, these migrants chose to settle in locations that bore a resemblance to the areas they had left behind in mainland China, hoklo immigrants from Quanzhou settled in coastal regions, and those from Zhangzhou tended to gather on inland plains, while the Hakka inhabited hilly areas. Clashes between these groups over land, water, and cultural differences led to the relocation of some communities, of about 40 million overseas Chinese worldwide, nearly 30 million live in Southeast Asia. They are collectively called Nanyang Chinese, according to a population genetic study, Singapore is the country with the biggest proportion of Hans in Southeast Asia. Up until the past few decades, overseas Han communities originated predominantly from areas in southern China, christmas Island has a Chinese majority at 70%, large Chinese populations also live in Malaysia and Thailand. Prior to the 1965 split, Malaysia and Singapore used to have the largest overseas Chinese population in the world and this position has since been taken by Thailand. The prehistory of the Han ethnic group is closely intertwined with both records and mythology. Han Chinese trace their ancestry from a confederation of late neolithic/early bronze-age agricultural tribes that lived along the Guanzhong, the Yellow Emperor is traditionally credited to have united with the neighbouring Shennong tribes after defeating their leader, Flame Emperor, at the Battle of Banquan
22.
Wuhan
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Wuhan is the capital of Hubei province, China, and is the most populous city in Central China. It lies in the eastern Jianghan Plain at the intersection of the reaches of the Yangtze. Because of its key role in transportation, Wuhan was sometimes referred to as the Chicago of China by foreign sources. Holding sub-provincial status, Wuhan is recognized as the political, economic, financial, cultural, educational, the city of Wuhan, first termed as such in 1927, has a population of 10,607,700 people as of 2015. In the 1920s, Wuhan was the capital of a leftist Kuomintang government led by Wang Jingwei in opposition to Chiang Kai-shek. At the 2010 census, its built-up area made of 8 out of 10 urban districts was home to 8,821,658 inhabitants, with a 3, 500-year-long history, Wuhan is one of the most ancient and civilized metropolitan cities in China. During the Han dynasty, Hanyang became a busy port. Around that time, walls were built to protect Hanyang and Wuchang, the latter event marks the foundation of Wuhan. In AD223, the Yellow Crane Tower was constructed on the Wuchang side of the Yangtze River, cui Hao, a celebrated poet of the Tang dynasty, visited the building in the early 8th century, his poem made it the most celebrated building in southern China. The city has long been renowned as a center for the arts, under the Mongol rulers, Wuchang was promoted to the status of provincial capital, by the dawn of the 18th century, Hankou had become one of Chinas top four most important towns of trade. In the late 19th century, railroads were extended on an axis through the city. Also during this period foreign powers extracted mercantile concessions, with the riverfront of Hankou being divided up into foreign-controlled merchant districts and these districts contained trading firm offices, warehouses, and docking facilities. On October 10,1911, Sun Yat-sens followers launched the Wuchang Uprising, Wuhan was the capital of a leftist Kuomintang government led by Wang Jingwei, in opposition to Chiang Kai-shek during the 1920s. S. As the battle raged on through 1938, Wuhan and the region had become the site of the Battle of Wuhan. After being taken by the Japanese in late 1938, Wuhan became a major Japanese logistics center for operations in southern China, in December 1944, the city was largely destroyed by U. S. firebombing raids conducted by the Fourteenth Air Force. In 1967, civil strife struck the city in the Wuhan Incident as a result of tensions arising out of the Cultural Revolution. The city has been subject to devastating floods, which are now supposed to be controlled by the ambitious Three Gorges Dam, a project which was completed in 2008. In December 1858, James Bruce, 8th Earl of Elgin, High Commissioner to China, and in the spring of 1861, Counselor Harry Parkes and Admiral Herbert were sent to Wuhan to open a trading port
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Manganese
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Manganese is a chemical element with symbol Mn and atomic number 25. It is not found as an element in nature, it is often found in minerals in combination with iron. Manganese is a metal with important industrial metal alloy uses, particularly in stainless steels, by the mid-18th century, Swedish chemist Carl Wilhelm Scheele had used pyrolusite to produce chlorine. Scheele and others were aware that pyrolusite contained a new element, johan Gottlieb Gahn was the first to isolate an impure sample of manganese metal in 1774, which he did by reducing the dioxide with carbon. Manganese phosphating is used for rust and corrosion prevention on steel, ionized manganese is used industrially as pigments of various colors, which depend on the oxidation state of the ions. The permanganates of alkali and alkaline earth metals are powerful oxidizers, Manganese dioxide is used as the cathode material in zinc-carbon and alkaline batteries. In biology, manganese ions function as cofactors for a variety of enzymes with many functions. Manganese enzymes are essential in detoxification of superoxide free radicals in organisms that must deal with elemental oxygen. Manganese also functions in the complex of photosynthetic plants. The element is a trace mineral for all known living organisms but is a neurotoxin. In larger amounts, and apparently with far greater effectiveness through inhalation, Manganese is a silvery-gray metal that resembles iron. It is hard and very brittle, difficult to fuse, Manganese metal and its common ions are paramagnetic. Manganese tarnishes slowly in air and oxidizes like iron in water containing dissolved oxygen, naturally occurring manganese is composed of one stable isotope, 55Mn. Eighteen radioisotopes have been isolated and described, the most stable being 53Mn with a half-life of 3.7 million years, 54Mn with a half-life of 312.3 days, and 52Mn with a half-life of 5.591 days. All of the radioactive isotopes have half-lives of less than three hours, and the majority of less than one minute. Manganese also has three meta states, Manganese is part of the iron group of elements, which are thought to be synthesized in large stars shortly before the supernova explosion. 53Mn decays to 53Cr with a half-life of 3.7 million years, because of its relatively short half-life, 53Mn is relatively rare, produced by cosmic rays impact on iron. Manganese isotopic contents are combined with chromium isotopic contents and have found application in isotope geology
24.
Tungsten
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Tungsten, also known as wolfram, is a chemical element with symbol W and atomic number 74. The word tungsten comes from the Swedish language tung sten, which translates to heavy stone. Its name in Swedish is volfram, however, in order to distinguish it from scheelite, a hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth almost exclusively in chemical compounds. It was identified as a new element in 1781, and first isolated as a metal in 1783 and its important ores include wolframite and scheelite. The free element is remarkable for its robustness, especially the fact that it has the highest melting point of all the elements discovered, melting at 3,422 °C,6,192 °F. Its high density is 19.3 times that of water, comparable to that of uranium and gold, polycrystalline tungsten is an intrinsically brittle and hard material, making it difficult to work. However, pure single-crystalline tungsten is more ductile, and can be cut with a hard-steel hacksaw, tungstens many alloys have numerous applications, including incandescent light bulb filaments, X-ray tubes, electrodes in TIG welding, superalloys, and radiation shielding. Tungstens hardness and high density give it military applications in penetrating projectiles, tungsten compounds are also often used as industrial catalysts. Tungsten is the metal from the third transition series that is known to occur in biomolecules. It is the heaviest element known to be essential to any living organism, tungsten interferes with molybdenum and copper metabolism and is somewhat toxic to animal life. In its raw form, tungsten is a hard metal that is often brittle. If made very pure, tungsten retains its hardness, and becomes malleable enough that it can be worked easily and it is worked by forging, drawing, or extruding. Tungsten objects are commonly formed by sintering. Of all metals in pure form, tungsten has the highest melting point, lowest vapor pressure, although carbon remains solid at higher temperatures than tungsten, carbon sublimes, rather than melts, so tungsten is considered to have a higher melting point. Tungsten has the lowest coefficient of expansion of any pure metal. The low thermal expansion and high melting point and tensile strength of tungsten originate from strong covalent bonds formed between tungsten atoms by the 5d electrons, alloying small quantities of tungsten with steel greatly increases its toughness. Tungsten exists in two crystalline forms, α and β. The former has a cubic structure and is the more stable form
25.
Molybdenum
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Molybdenum is a chemical element with symbol Mo and atomic number 42. The name is from Neo-Latin molybdaenum, from Ancient Greek Μόλυβδος molybdos, meaning lead, molybdenum minerals have been known throughout history, but the element was discovered in 1778 by Carl Wilhelm Scheele. The metal was first isolated in 1781 by Peter Jacob Hjelm, molybdenum does not occur naturally as a free metal on Earth, it is found only in various oxidation states in minerals. The free element, a metal with a gray cast, has the sixth-highest melting point of any element. It readily forms hard, stable carbides in alloys, and for this reason most of production of the element is used in steel alloys. Most molybdenum compounds have low solubility in water, but when molybdenum-bearing minerals contact oxygen and water, industrially, molybdenum compounds are used in high-pressure and high-temperature applications as pigments and catalysts. Molybdenum-bearing enzymes are by far the most common catalysts for breaking the chemical bond in atmospheric molecular nitrogen in the process of biological nitrogen fixation. At least 50 molybdenum enzymes are now known in bacteria and animals and these nitrogenases contain molybdenum in a form different from other molybdenum enzymes, which all contain fully oxidized molybdenum in a molybdenum cofactor. These various molybdenum cofactor enzymes are vital to the organisms, and molybdenum is an element for life in all higher eukaryote organisms. In its pure form, molybdenum is a metal with a Mohs hardness of 5.5. It has a point of 2,623 °C, of the naturally occurring elements, only tantalum, osmium, rhenium, tungsten. Weak oxidation of molybdenum starts at 300 °C and it has one of the lowest coefficients of thermal expansion among commercially used metals. The tensile strength of molybdenum wires increases about 3 times, from about 10 to 30 GPa, there are 35 known isotopes of molybdenum, ranging in atomic mass from 83 to 117, as well as four metastable nuclear isomers. Seven isotopes occur naturally, with masses of 92,94,95,96,97,98. Of these naturally occurring isotopes, only molybdenum-100 is unstable, molybdenum-98 is the most abundant isotope, comprising 24. 14% of all molybdenum. Molybdenum-100 has a half-life of about 1019 y and undergoes double beta decay into ruthenium-100, molybdenum isotopes with mass numbers from 111 to 117 all have half-lives of approximately 150 ns. All unstable isotopes of molybdenum decay into isotopes of niobium, technetium, as also noted below, the most common isotopic molybdenum application involves molybdenum-99, which is a fission product. It is a parent radioisotope to the short-lived gamma-emitting daughter radioisotope technetium-99m, in 2008, the Delft University of Technology applied for a patent on the molybdenum-98-based production of molybdenum-99
26.
Zinc
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Zinc is a chemical element with the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table, in some respects zinc is chemically similar to magnesium, both elements exhibit only one normal oxidation state, and the Zn2+ and Mg2+ ions are of similar size. Zinc is the 24th most abundant element in Earths crust and has five stable isotopes, the most common zinc ore is sphalerite, a zinc sulfide mineral. The largest workable lodes are in Australia, Asia, and the United States, Zinc is refined by froth flotation of the ore, roasting, and final extraction using electricity. Zinc metal was not produced on a large scale until the 12th century in India and was unknown to Europe until the end of the 16th century, the mines of Rajasthan have given definite evidence of zinc production going back to the 6th century BC. To date, the oldest evidence of pure zinc comes from Zawar, in Rajasthan, alchemists burned zinc in air to form what they called philosophers wool or white snow. The element was named by the alchemist Paracelsus after the German word Zinke. German chemist Andreas Sigismund Marggraf is credited with discovering pure metallic zinc in 1746, work by Luigi Galvani and Alessandro Volta uncovered the electrochemical properties of zinc by 1800. Corrosion-resistant zinc plating of iron is the application for zinc. Other applications are in batteries, small non-structural castings. A variety of compounds are commonly used, such as zinc carbonate and zinc gluconate, zinc chloride, zinc pyrithione, zinc sulfide. Zinc is an essential mineral perceived by the public today as being of exceptional biologic and public health importance, Zinc deficiency affects about two billion people in the developing world and is associated with many diseases. In children, deficiency causes growth retardation, delayed sexual maturation, infection susceptibility, enzymes with a zinc atom in the reactive center are widespread in biochemistry, such as alcohol dehydrogenase in humans. Consumption of excess zinc can cause ataxia, lethargy and copper deficiency, Zinc is a bluish-white, lustrous, diamagnetic metal, though most common commercial grades of the metal have a dull finish.6 pm. The metal is hard and brittle at most temperatures but becomes malleable between 100 and 150 °C, above 210 °C, the metal becomes brittle again and can be pulverized by beating. Zinc is a conductor of electricity. For a metal, zinc has relatively low melting and boiling points, the melting point is the lowest of all the transition metals aside from mercury and cadmium. Many alloys contain zinc, including brass, Other metals long known to form binary alloys with zinc are aluminium, antimony, bismuth, gold, iron, lead, mercury, silver, tin, magnesium, cobalt, nickel, tellurium, and sodium
27.
Cobalt
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Cobalt is a chemical element with symbol Co and atomic number 27. Like nickel, cobalt is found in the Earths crust only in chemically combined form, the free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal. In 1735, such ores were found to be reducible to a new metal, today, some cobalt is produced specifically from various metallic-lustered ores, for example cobaltite, but the main source of the element is as a by-product of copper and nickel mining. The copper belt in the Democratic Republic of the Congo, Central African Republic, cobalt is primarily used in the preparation of magnetic, wear-resistant and high-strength alloys. The compounds, cobalt silicate and cobalt aluminate give a deep blue color to glass, ceramics, inks, paints. Cobalt occurs naturally as only one isotope, cobalt-59. Cobalt-60 is an important radioisotope, used as a radioactive tracer. Cobalt is the center of coenzymes called cobalamins, the most common example of which is vitamin B12. As such, it is a trace dietary mineral for all animals. Cobalt in inorganic form is also a micronutrient for bacteria, algae, cobalt is a ferromagnetic metal with a specific gravity of 8.9. The Curie temperature is 1,115 °C and the moment is 1. 6–1.7 Bohr magnetons per atom. Cobalt has a relative permeability two-thirds that of iron, metallic cobalt occurs as two crystallographic structures, hcp and fcc. The ideal transition temperature between the hcp and fcc structures is 450 °C, but in practice, the difference is so small that random intergrowth of the two is common. Cobalt is a weakly reducing metal that is protected from oxidation by an oxide film. It is attacked by halogens and sulfur, heating in oxygen produces Co3O4 which loses oxygen at 900 °C to give the monoxide CoO. The metal reacts with fluorine at 520 K to give CoF3, with chlorine, bromine and iodine and it does not react with hydrogen gas or nitrogen gas even when heated, but it does react with boron, carbon, phosphorus, arsenic and sulfur. At ordinary temperatures, it reacts slowly with mineral acids, and very slowly with moist, common oxidation states of cobalt include +2 and +3, although compounds with oxidation states ranging from −3 to +5 are also known. A common oxidation state for simple compounds is +2 and these salts form the pink-colored metal aquo complex 2+ in water
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Gallium
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Gallium is a chemical element with symbol Ga and atomic number 31. It is in group 13 of the table, and thus has similarities to the other metals of the group, aluminium, indium. Gallium does not occur as an element in nature, but as gallium compounds in trace amounts in zinc ores. Elemental gallium is a soft, silvery blue metal at standard temperature and pressure, a solid at low temperatures. The melting point of gallium is used as a reference point. The alloy galinstan has a lower melting point of −19 °C. Since its discovery in 1875, gallium has been used to make alloys with low melting points and it is also used in semiconductors as a dopant in semiconductor substrates. Gallium is predominantly used in electronics, gallium arsenide, the primary chemical compound of gallium in electronics, is used in microwave circuits, high-speed switching circuits, and infrared circuits. Semiconductive gallium nitride and indium gallium nitride produce blue and violet light-emitting diodes, gallium is also used in the production of artificial gadolinium gallium garnet for jewelry. Gallium has no known role in biology. Gallium behaves in a manner to ferric salts in biological systems. Gallium is used in thermometers as a non-toxic and environmentally friendly alternative to mercury, elemental gallium is not found in nature, but it is easily obtained by smelting. Very pure gallium metal has a color and its solid metal fractures conchoidally like glass. Gallium liquid expands by 3. 1% when it solidifies, therefore, gallium shares the higher-density liquid state with a short list of other materials that includes water, silicon, germanium, antimony, bismuth, and plutonium. Gallium attacks most other metals by diffusing into the metal lattice, for example, it diffuses into the grain boundaries of aluminium-zinc alloys and steel, making them very brittle. Gallium easily alloys with metals, and is used in small quantities in the plutonium-gallium alloy in the plutonium cores of nuclear bombs to stabilize the plutonium crystal structure. The melting point of gallium, at 302.9146 K, is just above room temperature and this melting point is one of the formal temperature reference points in the International Temperature Scale of 1990 established by the International Bureau of Weights and Measures. The triple point of gallium,302.9166 K, is used by the US National Institute of Standards, the unique melting point of gallium allows it to melt in the human hand, and then refreeze if removed
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Thallium
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Thallium is a chemical element with symbol Tl and atomic number 81. This soft gray post-transition metal is not found free in nature, when isolated, thallium resembles tin, but discolors when exposed to air. Chemists William Crookes and Claude-Auguste Lamy discovered thallium independently in 1861, both used the newly developed method of flame spectroscopy, in which thallium produces a notable green spectral line. Thallium, from Greek θαλλός, thallos, meaning a green shoot or twig, was named by Crookes and it was isolated by both Lamy and Crookes in 1862, Lamy by electrolysis and Crookes by precipitation and melting of the resultant powder. Crookes exhibited it as a powder precipitated by zinc at the International exhibition which opened on 1 May, Thallium tends to oxidize to the +3 and +1 oxidation states as ionic salts. The +3 state resembles that of the elements in group 13. Commercially, however, thallium is produced not from potassium ores, approximately 60–70% of thallium production is used in the electronics industry, and the remainder is used in the pharmaceutical industry and in glass manufacturing. It is also used in infrared detectors, the radioisotope thallium-201 is used in small, nontoxic amounts as an agent in a nuclear medicine scan, during one type of nuclear cardiac stress test. Soluble thallium salts are toxic, and they were used in rat poisons. Use of these compounds has been restricted or banned in many countries, notably, thallium poisoning results in hair loss. Because of its popularity as a murder weapon, thallium has gained notoriety as the poisoners poison. A thallium atom has 81 electrons, arranged in the electron configuration 4f145d106s26p1, of these, however, due to the inert pair effect, the 6s electron pair is relativistically stabilised and it is more difficult to get them involved in chemical bonding than for the heavier elements. Thallium is malleable and sectile enough to be cut with a knife at room temperature and it has a metallic luster that, when exposed to air, quickly tarnishes to a bluish-gray tinge, resembling lead. It may be preserved by immersion in oil, a heavy layer of oxide builds up on thallium if left in air. In the presence of water, thallium hydroxide is formed, sulfuric and nitric acid dissolve thallium rapidly to make the sulfate and nitrate salts, while hydrochloric acid forms an insoluble thallium chloride layer. Thallium has 25 isotopes which have atomic masses that range from 184 to 210, 203Tl and 205Tl are the only stable isotopes and make up nearly all of natural thallium. 204Tl is the most stable radioisotope, with a half-life of 3.78 years and it is made by the neutron activation of stable thallium in a nuclear reactor. It is the most popular isotope used for thallium nuclear cardiac stress tests, Thallium compounds resemble the corresponding aluminium compounds
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Germanium
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Germanium is a chemical element with symbol Ge and atomic number 32. It is a lustrous, hard, grayish-white metalloid in the group, chemically similar to its group neighbors tin. Pure germanium is a semiconductor with a similar to elemental silicon. Like silicon, germanium naturally reacts and forms complexes with oxygen in nature, unlike silicon, it is too reactive to be found naturally on Earth in the free state. Because it seldom appears in high concentration, germanium was discovered late in the history of chemistry. Germanium ranks near fiftieth in relative abundance of the elements in the Earths crust, in 1869, Dmitri Mendeleev predicted its existence and some of its properties from its position on his periodic table, and called the element ekasilicon. Nearly two decades later, in 1886, Clemens Winkler found the new element along with silver and sulfur, although the new element somewhat resembled arsenic and antimony in appearance, the combining ratios in compounds agreed with Mendeleevs predictions for a relative of silicon. Winkler named the element after his country, Germany, today, germanium is mined primarily from sphalerite, though germanium is also recovered commercially from silver, lead, and copper ores. Germanium metal is used as a semiconductor in transistors and various electronic devices. Historically, the first decade of semiconductor electronics was based entirely on germanium, today, the amount of germanium produced for semiconductor electronics is one fiftieth the amount of ultra-high purity silicon produced for the same. Presently, the end uses are fibre-optic systems, infrared optics, solar cell applications. Germanium compounds are used for polymerization catalysts and have most recently found use in the production of nanowires. This element forms a number of organometallic compounds, such as tetraethylgermane. Germanium is not thought to be an element for any living organism. Some complex organic compounds are being investigated as possible pharmaceuticals. Similar to silicon and aluminum, natural germanium compounds tend to be insoluble in water, however, synthetic soluble germanium salts are nephrotoxic, and synthetic chemically reactive germanium compounds with halogens and hydrogen are irritants and toxins. Because of its position in his Periodic Table, Mendeleev called it ekasilicon, in mid-1885, at a mine near Freiberg, Saxony, a new mineral was discovered and named argyrodite because of the high silver content. The chemist Clemens Winkler analyzed this new mineral, which proved to be a combination of silver, sulfur, Winkler was able to isolate the new element in 1886 and found it similar to antimony
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Indium
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Indium is a chemical element with symbol In and atomic number 49. It is a metal that makes up 0.21 parts per million of the Earths crust. Very soft and malleable, indium has a point higher than sodium and gallium. Chemically, indium is similar to gallium and thallium, and it is intermediate between the two in terms of its properties. Indium was discovered in 1863 by Ferdinand Reich and Hieronymous Theodor Richter by spectroscopic methods and they named it for the indigo blue line in its spectrum. Indium was isolated the next year, Indium is a minor component in zinc sulfide ores and is produced as a byproduct of zinc refinement. Indium has no role, though its compounds are somewhat toxic when injected into the bloodstream. Most occupational exposure is through ingestion, from which indium compounds are not absorbed well, Indium is a silvery-white, highly ductile post-transition metal with a bright luster. It is so soft that like sodium, it can be cut with a knife and it also leaves a visible line on paper. It is a member of group 13 on the periodic table, like tin, a high-pitched cry is heard when indium is bent – a crackling sound due to crystal twinning. Like gallium, indium is able to wet glass, like both, indium has a low melting point,156.60 °C, higher than its lighter homologue, gallium, but lower than its heavier homologue, thallium, and lower than tin. The density of indium,7.31 g/cm3, is greater than gallium. Below the critical temperature,3.41 K, indium becomes a superconductor, Indium displays a ductile viscoplastic response, found to be size-independent in tension and compression. However it does have an effect in bending and indentation, associated to a length-scale of order 50–100 µm. Indium has 49 electrons, with a configuration of 4d105s25p1. In compounds, indium most commonly donates the three outermost electrons to become indium, In3+, in some cases, the pair of 5s-electrons are not donated, resulting in indium, In+. The stabilization of the monovalent state is attributed to the inert pair effect, in which relativistic effects stabilize the 5s-orbital, thallium shows an even stronger effect, causing oxidation to thallium to be more probable than to thallium, whereas gallium commonly shows only the +3 oxidation state. Thus, although thallium is a strong oxidizing agent, indium is not
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Selenium
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Selenium is a chemical element with symbol Se and atomic number 34. It is a nonmetal with properties that are intermediate between the elements above and below in the table, sulfur and tellurium. It rarely occurs in its state or as pure ore compounds in the Earths crust. Selenium was discovered in 1817 by Jöns Jacob Berzelius, who noted the similarity of the new element to the previously discovered tellurium, Selenium is found in metal sulfide ores, where it partially replaces the sulfur. Commercially, selenium is produced as a byproduct in the refining of these ores, minerals that are pure selenide or selenate compounds are known but rare. The chief commercial uses for selenium today are glassmaking and pigments, Selenium is a semiconductor and is used in photocells. Applications in electronics, once important, have been supplanted by silicon semiconductor devices. Selenium is still used in a few types of DC power surge protectors, Selenium salts are toxic in large amounts, but trace amounts are necessary for cellular function in many organisms, including all animals. Selenium is an ingredient in multivitamins and other dietary supplements. It is a component of the antioxidant enzymes glutathione peroxidase and thioredoxin reductase and it is also found in three deiodinase enzymes, which convert one thyroid hormone to another. Selenium requirements in plants differ by species, with some plants requiring relatively large amounts, Selenium forms several allotropes that interconvert with temperature changes, depending somewhat on the rate of temperature change. When prepared in chemical reactions, selenium is usually an amorphous, when rapidly melted, it forms the black, vitreous form, usually sold commercially as beads. The structure of black selenium is irregular and complex and consists of rings with up to 1000 atoms per ring. Black Se is a brittle, lustrous solid that is soluble in CS2. Upon heating, it softens at 50 °C and converts to gray selenium at 180 °C, the red α, β, and γ forms are produced from solutions of black selenium by varying the evaporation rate of the solvent. They all have low, monoclinic crystal symmetries and contain nearly identical puckered Se8 rings with different arrangements. The packing is most dense in the α form, in the Se8 rings, the Se-Se distance is 233.5 pm and Se-Se-Se angle is 105. 7°. Other selenium allotropes may contain Se6 or Se7 rings, the most stable and dense form of selenium is gray and has a hexagonal crystal lattice consisting of helical polymeric chains, where the Se-Se distance is 237.3 pm and Se-Se-Se angle is 130. 1°
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Tellurium
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Tellurium is a chemical element with symbol Te and atomic number 52. It is a brittle, mildly toxic, rare, silver-white metalloid, Tellurium is chemically related to selenium and sulfur. It is occasionally found in form as elemental crystals. Tellurium is far more common in the universe as a whole than on Earth, Tellurium was discovered in the Habsburg Empire, in 1782 by Franz-Joseph Müller von Reichenstein in a mineral containing tellurium and gold. Martin Heinrich Klaproth named the new element in 1798 after the Latin word for earth, gold telluride minerals are the most notable natural gold compounds. However, they are not a significant source of tellurium itself. Commercially, the use of tellurium is copper and steel alloys. Applications in CdTe solar panels and semiconductors also consume a portion of tellurium production. Tellurium has no function, although fungi can use it in place of sulfur. In humans, tellurium is partly metabolized into dimethyl telluride, 2Te, Tellurium has two allotropes, crystalline and amorphous. When crystalline, tellurium is silvery-white with a metallic luster and it is a brittle and easily pulverized metalloid. Amorphous tellurium is a black-brown powder prepared by precipitating it from a solution of acid or telluric acid. Tellurium is a semiconductor that shows a greater electrical conductivity in certain directions depending on atomic alignment, when molten, tellurium is corrosive to copper, iron, and stainless steel. Of the chalcogens, tellurium has the highest melting and boiling points, at 722.66 K and 1,261 K, Tellurium adopts a polymeric structure consisting of zig-zag chains of Te atoms. This gray material resists oxidation by air and is not volatile, naturally occurring tellurium has eight isotopes. Six of those isotopes, 120Te, 122Te, 123Te, 124Te, 125Te and 126Te, are stable, the other two, 128Te and 130Te, have been found to be slightly radioactive, with extremely long half-lives, including 2.2 ×1024 years for 128Te. This is the longest known half life among all radionuclides and is approximately 160 trillion times the age of the known universe, stable isotopes comprise only 33. 2% of naturally occurring tellurium. A further thirty artificial radioisotopes of tellurium are known with atomic masses ranging from 105 to 142, there are also 17 nuclear isomers, with half lives of up to 154 days
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Sulfur
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Sulfur or sulphur is a chemical element with symbol S and atomic number 16. It is abundant, multivalent, and nonmetallic, under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a yellow crystalline solid at room temperature. Chemically, sulfur reacts with all elements except for gold, platinum, iridium, tellurium, though sometimes found in pure, native form, sulfur usually occurs as sulfide and sulfate minerals. Being abundant in native form, sulfur was known in ancient times, being mentioned for its uses in ancient India, ancient Greece, China, in the Bible, sulfur is called brimstone. Today, almost all elemental sulfur is produced as a byproduct of removing sulfur-containing contaminants from natural gas, the greatest commercial use of the element is the production of sulfuric acid for sulfate and phosphate fertilizers, and other chemical processes. The element sulfur is used in matches, insecticides, and fungicides, many sulfur compounds are odoriferous, and the smells of odorized natural gas, skunk scent, grapefruit, and garlic are due to organosulfur compounds. Hydrogen sulfide gives the characteristic odor to rotting eggs and other biological processes, sulfur is an essential element for all life, but almost always in the form of organosulfur compounds or metal sulfides. Three amino acids and two vitamins are organosulfur compounds, many cofactors also contain sulfur including glutathione and thioredoxin and iron–sulfur proteins. Disulfides, S–S bonds, confer mechanical strength and insolubility of the keratin, found in outer skin, hair. Sulfur is one of the chemical elements needed for biochemical functioning and is an elemental macronutrient for all organisms. Sulfur is derived from the Latin word sulpur, which was Hellenized to sulphur, the spelling sulfur appears toward the end of the Classical period. In 12th-century Anglo-French, it was sulfre, in the 14th century the Latin ph was restored, for sulphre, the parallel f~ph spellings continued in Britain until the 19th century, when the word was standardized as sulphur. Sulfur was the form chosen in the United States, whereas Canada uses both, the IUPAC adopted the spelling sulfur in 1990, as did the Nomenclature Committee of the Royal Society of Chemistry in 1992, restoring the spelling sulfur to Britain. Sulfur forms polyatomic molecules with different chemical formulas, the best-known allotrope being octasulfur, cyclo-S8. The point group of cyclo-S8 is D4d and its dipole moment is 0 D. Octasulfur is a soft, bright-yellow solid that is odorless and it melts at 115.21 °C, boils at 444.6 °C and sublimes easily. At 95.2 °C, below its melting temperature, cyclo-octasulfur changes from α-octasulfur to the β-polymorph, the structure of the S8 ring is virtually unchanged by this phase change, which affects the intermolecular interactions. At higher temperatures, the viscosity decreases as depolymerization occurs, molten sulfur assumes a dark red color above 200 °C
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Calcite
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Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate. The Mohs scale of hardness, based on scratch hardness comparison. Other polymorphs of calcium carbonate are the minerals aragonite and vaterite, aragonite will change to calcite at 380–470 °C, and vaterite is even less stable. Calcite is derived from the German Calcit, a term coined in the 19th century from the Latin word for lime and it is thus etymologically related to chalk. Calcite crystals are trigonal-rhombohedral, though actual calcite rhombohedra are rare as natural crystals, however, they show a remarkable variety of habits including acute to obtuse rhombohedra, tabular forms, prisms, or various scalenohedra. Calcite exhibits several twinning types adding to the variety of observed forms and it may occur as fibrous, granular, lamellar, or compact. Cleavage is usually in three directions parallel to the rhombohedron form and its fracture is conchoidal, but difficult to obtain. It has a defining Mohs hardness of 3, a gravity of 2.71. Color is white or none, though shades of gray, red, orange, yellow, green, blue, violet, brown, calcite is transparent to opaque and may occasionally show phosphorescence or fluorescence. A transparent variety called Iceland spar is used for optical purposes, acute scalenohedral crystals are sometimes referred to as dogtooth spar while the rhombohedral form is sometimes referred to as nailhead spar. Single calcite crystals display an optical property called birefringence and this strong birefringence causes objects viewed through a clear piece of calcite to appear doubled. The birefringent effect was first described by the Danish scientist Rasmus Bartholin in 1669, at a wavelength of ~590 nm calcite has ordinary and extraordinary refractive indices of 1.658 and 1.486, respectively. Between 190 and 1700 nm, the refractive index varies roughly between 1.9 and 1.5, while the extraordinary refractive index varies between 1.6 and 1.4. Calcite, like most carbonates, will dissolve with most forms of acid, calcite can be either dissolved by groundwater or precipitated by groundwater, depending on several factors including the water temperature, pH, and dissolved ion concentrations. Although calcite is fairly insoluble in water, acidity can cause dissolution of calcite. Ambient carbon dioxide, due to its acidity, has a slight solubilizing effect on calcite, calcite exhibits an unusual characteristic called retrograde solubility in which it becomes less soluble in water as the temperature increases. When conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together or it can fill fractures. On a landscape scale, continued dissolution of calcium carbonate-rich rocks can lead to the expansion and eventual collapse of cave systems, high-grade optical calcite was used in World War II for gun sights, specifically in bomb sights and anti-aircraft weaponry
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Limestone
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Limestone is a sedimentary rock, composed mainly of skeletal fragments of marine organisms such as coral, forams and molluscs. Its major materials are the minerals calcite and aragonite, which are different crystal forms of calcium carbonate, about 10% of sedimentary rocks are limestones. The solubility of limestone in water and weak acid solutions leads to karst landscapes, most cave systems are through limestone bedrock. The first geologist to distinguish limestone from dolomite was Belsazar Hacquet in 1778, like most other sedimentary rocks, most limestone is composed of grains. Most grains in limestone are skeletal fragments of organisms such as coral or foraminifera. Other carbonate grains comprising limestones are ooids, peloids, intraclasts and these organisms secrete shells made of aragonite or calcite, and leave these shells behind when they die. Limestone often contains variable amounts of silica in the form of chert or siliceous skeletal fragment, some limestones do not consist of grains at all, and are formed completely by the chemical precipitation of calcite or aragonite, i. e. travertine. Secondary calcite may be deposited by supersaturated meteoric waters and this produces speleothems, such as stalagmites and stalactites. Another form taken by calcite is oolitic limestone, which can be recognized by its granular appearance, the primary source of the calcite in limestone is most commonly marine organisms. Some of these organisms can construct mounds of rock known as reefs, below about 3,000 meters, water pressure and temperature conditions cause the dissolution of calcite to increase nonlinearly, so limestone typically does not form in deeper waters. Limestones may also form in lacustrine and evaporite depositional environments, calcite can be dissolved or precipitated by groundwater, depending on several factors, including the water temperature, pH, and dissolved ion concentrations. Calcite exhibits a characteristic called retrograde solubility, in which it becomes less soluble in water as the temperature increases. Impurities will cause limestones to exhibit different colors, especially with weathered surfaces, Limestone may be crystalline, clastic, granular, or massive, depending on the method of formation. Crystals of calcite, quartz, dolomite or barite may line small cavities in the rock, when conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together, or it can fill fractures. Travertine is a banded, compact variety of limestone formed along streams, particularly there are waterfalls. Calcium carbonate is deposited where evaporation of the leaves a solution supersaturated with the chemical constituents of calcite. Tufa, a porous or cellular variety of travertine, is found near waterfalls, coquina is a poorly consolidated limestone composed of pieces of coral or shells. During regional metamorphism that occurs during the building process, limestone recrystallizes into marble
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Celestine (mineral)
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Celestine or celestite is a mineral consisting of strontium sulfate. The mineral is named for its occasional delicate blue color, celestine is the principal source of the element strontium, commonly used in fireworks and in various metal alloys. Celestine derives its name from the Latin word caelestis meaning celestial, celestine occurs as crystals, and also in compact massive and fibrous forms. It is mostly found in rocks, often associated with the minerals gypsum, anhydrite. The mineral is found worldwide, usually in small quantities, pale blue crystal specimens are found in Madagascar. The skeletons of the protozoan Acantharea are made of celestine, unlike those of other radiolarians which are made of silica, in carbonate marine sediments, burial dissolution is a recognised mechanism of celestine precipitation. It is sometimes used as a gemstone, celestine crystals are found in some geodes. The worlds largest known geode, a celestine geode 35 feet in diameter at its widest point, is located near the village of Put-in-Bay, Ohio, on South Bass Island in Lake Erie. The geode has been converted into a cave, Crystal Cave. The geode has celestine crystals as wide as 18 inches across, estimated to weigh up to 300 pounds each
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