1.
Lighting
–
Lighting or illumination is the deliberate use of light to achieve a practical or aesthetic effect. Lighting includes the use of artificial light sources like lamps and light fixtures, as well as natural illumination by capturing daylight. Daylighting is sometimes used as the source of light during daytime in buildings. This can save energy in place of using lighting, which represents a major component of energy consumption in buildings. Proper lighting can enhance performance, improve the appearance of an area. Indoor lighting is accomplished using light fixtures, and is a key part of interior design. Lighting can also be a component of landscape projects. With the discovery of fire, the earliest form of lighting used to illuminate an area were campfires or torches. As early as 400,000 BCE, fire was kindled in the caves of Peking Man, prehistoric people used primitive oil lamps to illuminate surroundings. These lamps were made from naturally occurring materials such as rocks, shells, horns and stones, were filled with grease, lamps typically used animal or vegetable fats as fuel. Hundreds of these lamps have been found in the Lascaux caves in modern-day France, oily animals were also used as lamps after being threaded with a wick. Fireflies have been used as lighting sources, candles and glass and pottery lamps were also invented. Chandeliers were a form of light fixture. A major reduction in the cost of lighting occurred with the discovery of whale oil, in 1849, Dr. Abraham Gesner, a Canadian geologist, devised a method where kerosene could be distilled from petroleum. Earlier coal-gas methods had been used for lighting since the 1820s, gesners kerosene was cheap, easy to produce, could be burned in existing lamps, and did not produce an offensive odor as did most whale oil. It could be stored indefinitely unlike whale oil, which would eventually spoil, the American petroleum boom began in the 1850s. By the end of the decade there were 30 kerosene plants operating in the United States, the cheaper, more efficient fuel began to drive whale oil out of the market. John D. Rockefeller was most responsible for the success of kerosene
2.
Budapest
–
Budapest is the capital and most populous city of Hungary, one of the largest cities in the European Union and sometimes described as the primate city of Hungary. It has an area of 525 square kilometres and a population of about 1.8 million within the limits in 2016. Budapest became a single city occupying both banks of the Danube river with the unification of Buda and Óbuda on the west bank, the history of Budapest began with Aquincum, originally a Celtic settlement that became the Roman capital of Lower Pannonia. Hungarians arrived in the territory in the 9th century and their first settlement was pillaged by the Mongols in 1241–1242. The re-established town became one of the centres of Renaissance humanist culture by the 15th century, following the Battle of Mohács and nearly 150 years of Ottoman rule, the region entered a new age of prosperity, and Budapest became a global city after its unification in 1873. It also became the co-capital of the Austro-Hungarian Empire, a power that dissolved in 1918. Budapest was the point of the Hungarian Revolution of 1848, the Hungarian Republic of Councils in 1919, the Battle of Budapest in 1945. Budapest is an Alpha- global city, with strengths in arts, commerce, design, education, entertainment, fashion, finance, healthcare, media, services, research, and tourism. Its business district hosts the Budapest Stock Exchange and the headquarters of the largest national and international banks and it is the highest ranked Central and Eastern European city on Innovation Cities Top 100 index. Budapest attracts 4.4 million international tourists per year, making it the 25th most popular city in the world, further famous landmarks include Andrássy Avenue, St. It has around 80 geothermal springs, the worlds largest thermal water system, second largest synagogue. Budapest is home to the headquarters of the European Institute of Innovation and Technology, the European Police College, over 40 colleges and universities are located in Budapest, including the Eötvös Loránd University, Central European University and Budapest University of Technology and Economics. Budapest is the combination of the city names Buda and Pest, One of the first documented occurrences of the combined name Buda-Pest was in 1831 in the book Világ, written by Count István Széchenyi. The origins of the names Buda and Pest are obscure, according to chronicles from the Middle Ages, the name Buda comes from the name of its founder, Bleda, brother of the Hunnic ruler Attila. The theory that Buda was named after a person is also supported by modern scholars, an alternative explanation suggests that Buda derives from the Slavic word вода, voda, a translation of the Latin name Aquincum, which was the main Roman settlement in the region. There are also theories about the origin of the name Pest. One of the states that the word Pest comes from the Roman times. According to another theory, Pest originates from the Slavic word for cave, or oven, the first settlement on the territory of Budapest was built by Celts before 1 AD
3.
Hungary
–
Hungary is a unitary parliamentary republic in Central Europe. With about 10 million inhabitants, Hungary is a member state of the European Union. The official language is Hungarian, which is the most widely spoken language in Europe. Hungarys capital and largest metropolis is Budapest, a significant economic hub, major urban areas include Debrecen, Szeged, Miskolc, Pécs and Győr. His great-grandson Stephen I ascended to the throne in 1000, converting the country to a Christian kingdom, by the 12th century, Hungary became a middle power within the Western world, reaching a golden age by the 15th century. Hungarys current borders were established in 1920 by the Treaty of Trianon after World War I, when the country lost 71% of its territory, 58% of its population, following the interwar period, Hungary joined the Axis Powers in World War II, suffering significant damage and casualties. Hungary became a state of the Soviet Union, which contributed to the establishment of a four-decade-long communist dictatorship. On 23 October 1989, Hungary became again a democratic parliamentary republic, in the 21st century, Hungary is a middle power and has the worlds 57th largest economy by nominal GDP, as well as the 58th largest by PPP, out of 188 countries measured by the IMF. As a substantial actor in several industrial and technological sectors, it is both the worlds 36th largest exporter and importer of goods, Hungary is a high-income economy with a very high standard of living. It keeps up a security and universal health care system. Hungary joined the European Union in 2004 and part of the Schengen Area since 2007, Hungary is a member of the United Nations, NATO, WTO, World Bank, the AIIB, the Council of Europe and Visegrád Group. Well known for its cultural history, Hungary has been contributed significantly to arts, music, literature, sports and science. Hungary is the 11th most popular country as a tourist destination in Europe and it is home to the largest thermal water cave system, the second largest thermal lake in the world, the largest lake in Central Europe, and the largest natural grasslands in Europe. The H in the name of Hungary is most likely due to historical associations with the Huns. The rest of the word comes from the Latinized form of Medieval Greek Oungroi, according to an explanation the Greek name was borrowed from Proto-Slavic Ǫgǔri, in turn borrowed from Oghur-Turkic Onogur. Onogur was the name for the tribes who later joined the Bulgar tribal confederacy that ruled the eastern parts of Hungary after the Avars. The Hungarians likely belonged to the Onogur tribal alliance and it is possible they became its ethnic majority. The Hungarian endonym is Magyarország, composed of magyar and ország, the word magyar is taken from the name of one of the seven major semi-nomadic Hungarian tribes, magyeri
4.
Tungsten
–
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
5.
World War I
–
World War I, also known as the First World War, the Great War, or the War to End All Wars, was a global war originating in Europe that lasted from 28 July 1914 to 11 November 1918. More than 70 million military personnel, including 60 million Europeans, were mobilised in one of the largest wars in history and it was one of the deadliest conflicts in history, and paved the way for major political changes, including revolutions in many of the nations involved. The war drew in all the worlds great powers, assembled in two opposing alliances, the Allies versus the Central Powers of Germany and Austria-Hungary. These alliances were reorganised and expanded as more nations entered the war, Italy, Japan, the trigger for the war was the assassination of Archduke Franz Ferdinand of Austria, heir to the throne of Austria-Hungary, by Yugoslav nationalist Gavrilo Princip in Sarajevo on 28 June 1914. This set off a crisis when Austria-Hungary delivered an ultimatum to the Kingdom of Serbia. Within weeks, the powers were at war and the conflict soon spread around the world. On 25 July Russia began mobilisation and on 28 July, the Austro-Hungarians declared war on Serbia, Germany presented an ultimatum to Russia to demobilise, and when this was refused, declared war on Russia on 1 August. Germany then invaded neutral Belgium and Luxembourg before moving towards France, after the German march on Paris was halted, what became known as the Western Front settled into a battle of attrition, with a trench line that changed little until 1917. On the Eastern Front, the Russian army was successful against the Austro-Hungarians, in November 1914, the Ottoman Empire joined the Central Powers, opening fronts in the Caucasus, Mesopotamia and the Sinai. In 1915, Italy joined the Allies and Bulgaria joined the Central Powers, Romania joined the Allies in 1916, after a stunning German offensive along the Western Front in the spring of 1918, the Allies rallied and drove back the Germans in a series of successful offensives. By the end of the war or soon after, the German Empire, Russian Empire, Austro-Hungarian Empire, national borders were redrawn, with several independent nations restored or created, and Germanys colonies were parceled out among the victors. During the Paris Peace Conference of 1919, the Big Four imposed their terms in a series of treaties, the League of Nations was formed with the aim of preventing any repetition of such a conflict. This effort failed, and economic depression, renewed nationalism, weakened successor states, and feelings of humiliation eventually contributed to World War II. From the time of its start until the approach of World War II, at the time, it was also sometimes called the war to end war or the war to end all wars due to its then-unparalleled scale and devastation. In Canada, Macleans magazine in October 1914 wrote, Some wars name themselves, during the interwar period, the war was most often called the World War and the Great War in English-speaking countries. Will become the first world war in the sense of the word. These began in 1815, with the Holy Alliance between Prussia, Russia, and Austria, when Germany was united in 1871, Prussia became part of the new German nation. Soon after, in October 1873, German Chancellor Otto von Bismarck negotiated the League of the Three Emperors between the monarchs of Austria-Hungary, Russia and Germany
6.
Vacuum tube
–
In electronics, a vacuum tube, an electron tube, or just a tube, or valve, is a device that controls electric current between electrodes in an evacuated container. Vacuum tubes mostly rely on thermionic emission of electrons from a hot filament or a cathode heated by the filament and this type is called a thermionic tube or thermionic valve. A phototube, however, achieves electron emission through the photoelectric effect, the simplest vacuum tube, the diode, contains only a heater, a heated electron-emitting cathode, and a plate. Current can only flow in one direction through the device between the two electrodes, as electrons emitted by the travel through the tube and are collected by the anode. Adding one or more control grids within the tube allows the current between the cathode and anode to be controlled by the voltage on the grid or grids, Tubes with grids can be used for many purposes, including amplification, rectification, switching, oscillation, and display. In the 1940s the invention of devices made it possible to produce solid-state devices, which are smaller, more efficient, more reliable, more durable. Hence, from the mid-1950s solid-state devices such as transistors gradually replaced tubes, the cathode-ray tube remained the basis for televisions and video monitors until superseded in the 21st century. However, there are still a few applications for which tubes are preferred to semiconductors, for example, the used in microwave ovens. One classification of vacuum tubes is by the number of active electrodes, a device with two active elements is a diode, usually used for rectification. Devices with three elements are used for amplification and switching. Additional electrodes create tetrodes, pentodes, and so forth, which have additional functions made possible by the additional controllable electrodes. X-ray tubes are vacuum tubes. Phototubes and photomultipliers rely on electron flow through a vacuum, though in those cases electron emission from the cathode depends on energy from photons rather than thermionic emission, since these sorts of vacuum tubes have functions other than electronic amplification and rectification they are described in their own articles. A vacuum tube consists of two or more electrodes in a vacuum inside an airtight enclosure, most tubes have glass envelopes, though ceramic and metal envelopes have been used. The electrodes are attached to leads which pass through the envelope via an airtight seal, Tubes were a frequent cause of failure in electronic equipment, and consumers were expected to be able to replace tubes themselves. In addition to the terminals, some tubes had an electrode terminating at a top cap. The principal reason for doing this was to avoid leakage resistance through the tube base, the bases were commonly made with phenolic insulation which performs poorly as an insulator in humid conditions. There was even a design that had two top cap connections
7.
General Electric
–
General Electric, often abbreviated as GE, is an American multinational conglomerate corporation incorporated in New York and headquartered in Boston, Massachusetts. In 2011, GE ranked among the Fortune 500 as the 68th-largest firm in the U. S. by gross revenue, as of 2012, the company was listed the fourth-largest in the world among the Forbes Global 2000, further metrics being taken into account. The Nobel Prize has twice been awarded to employees of General Electric, Irving Langmuir in 1932, on January 13,2016, it was announced that GE will be moving its corporate headquarters from Fairfield, Connecticut to the South Boston Waterfront neighborhood of Boston, Massachusetts. The first group of workers arrived in the summer of 2016, morgan and the Vanderbilt family for Edisons lighting experiments. The new company also acquired Sprague Electric Railway & Motor Company in the same year, both plants continue to operate under the GE banner to this day. The company was incorporated in New York, with the Schenectady plant used as headquarters for years thereafter. Around the same time, General Electrics Canadian counterpart, Canadian General Electric, was formed, in 1896, General Electric was one of the original 12 companies listed on the newly formed Dow Jones Industrial Average. After 120 years, it is the one of the original companies still listed on the Dow index. In 1911, General Electric absorbed the National Electric Lamp Association into its lighting business, GE established its lighting division headquarters at Nela Park in East Cleveland, Ohio. Nela Park is still the headquarters for GEs lighting business, owen D. Young, through GE, founded the Radio Corporation of America in 1919 to further international radio. GE used RCA as its retail arm for radio sales from 1919, in 1927, Ernst Alexanderson of GE made the first demonstration of his television broadcasts at his General Electric Realty Plot home at 1132 Adams Rd, Schenectady, NY. The sound was broadcast on GEs WGY, experimental television station W2XAD evolved into station WRGB which—along with WGY and WGFM —was owned and operated by General Electric until 1983. GEs history of working with turbines in the field gave them the engineering know-how to move into the new field of aircraft turbosuperchargers. Led by Sanford Alexander Moss, GE introduced the first superchargers during World War I, superchargers became indispensable in the years immediately prior to World War II, and GE was the world leader in exhaust-driven supercharging when the war started. This experience, in turn, made GE a natural selection to develop the Whittle W.1 jet engine that was demonstrated in the United States in 1941, GE ranked ninth among United States corporations in the value of wartime production contracts. In 2002, GE acquired the assets of Enron during its bankruptcy proceedings. Some consumers boycotted GE light bulbs, refrigerators and other products in the 1980s and 1990s to protest GEs role in weapons production. With IBM, Burroughs, NCR, Control Data Corporation, Honeywell, RCA and UNIVAC, GE had a line of general purpose and special purpose computers
8.
Brand
–
A brand is a name, term, design, symbol, or other feature that distinguishes one seller’s product from those of others. Brands are used in business, marketing, and advertising, however, the term has been extended to mean a strategic personality for a product or company, so that ‘brand’ now suggests the values and promises that a consumer may perceive and buy into. Branding is a set of marketing and communication methods that help to distinguish a company from competitors, the key components that form a brands toolbox include a brand’s identity, brand communication, brand awareness, brand loyalty, and various branding strategies. Brand equity is the totality of a brands worth and is validated by assessing the effectiveness of these branding components. To reach such an invaluable brand prestige requires a commitment to a way of doing business. A corporation who exhibits a strong brand culture is dedicated on producing intangible outputs such as customer satisfaction, reduced price sensitivity and customer loyalty. A brand is in essence a promise to its customers that they can expect long-term security, when a customer is familiar with a brand or favours it incomparably to its competitors, this is when a corporation has reached a high level of brand equity. Many companies are beginning to understand there is often little to differentiate between products in the 21st century. Branding remains the last bastion for differentiation, in accounting, a brand defined as an intangible asset is often the most valuable asset on a corporation’s balance sheet. The word ‘brand’ is often used as a referring to the company that is strongly identified with a brand. Marque or make are often used to denote a brand of motor vehicle, a concept brand is a brand that is associated with an abstract concept, like breast cancer awareness or environmentalism, rather than a specific product, service, or business. A commodity brand is a associated with a commodity. The word, brand, derives from Dutch brand meaning to burn and this product was developed at Dhosi Hill, an extinct volcano in northern India. Roman glassmakers branded their works, with Ennion being the most prominent, the Italians used brands in the form of watermarks on paper in the 13th century. Blind Stamps, hallmarks, and silver-makers marks are all types of brand, industrialization moved the production of many household items, such as soap, from local communities to centralized factories. When shipping their items, the factories would literally brand their logo or insignia on the barrels used, Bass & Company, the British brewery, claims their red-triangle brand as the worlds first trademark. Another example comes from Antiche Fornaci Giorgi in Italy, which has stamped or carved its bricks with the same proto-logo since 1731, cattle-branding has been used since Ancient Egypt. The term, maverick, originally meaning an un-branded calf, came from a Texas pioneer rancher, Sam Maverick, use of the word maverick spread among cowboys and came to apply to unbranded calves found wandering alone
9.
Manufacturing
–
Manufacturing is the value added to production of merchandise for use or sale using labour and machines, tools, chemical and biological processing, or formulation. Manufacturing engineering or manufacturing process are the steps through which raw materials are transformed into a final product, the manufacturing process begins with the product design, and materials specification from which the product is made. These materials are modified through manufacturing processes to become the required part. Manufacturing takes turns under all types of economic systems, in a free market economy, manufacturing is usually directed toward the mass production of products for sale to consumers at a profit. In a collectivist economy, manufacturing is more directed by the state to supply a centrally planned economy. In mixed market economies, manufacturing occurs under some degree of government regulation, modern manufacturing includes all intermediate processes required the production and integration of a products components. Some industries, such as semiconductor and steel manufacturers use the term fabrication instead, the manufacturing sector is closely connected with engineering and industrial design. Examples of major manufacturers in North America include General Motors Corporation, General Electric, Procter & Gamble, General Dynamics, Boeing, Pfizer, examples in Europe include Volkswagen Group, Siemens, and Michelin. Examples in Asia include Sony, Huawei, Lenovo, Toyota, Samsung, in its earliest form, manufacturing was usually carried out by a single skilled artisan with assistants. In much of the world, the guild system protected the privileges. Before the Industrial Revolution, most manufacturing occurred in rural areas, entrepreneurs organized a number of manufacturing households into a single enterprise through the putting-out system. Toll manufacturing is an arrangement whereby a first firm with specialized equipment processes raw materials or semi-finished goods for a second firm, manufacturing provides important material support for national infrastructure and for national defense. On the other hand, most manufacturing may involve significant social and environmental costs, the clean-up costs of hazardous waste, for example, may outweigh the benefits of a product that creates it. Hazardous materials may expose workers to health risks and these costs are now well known and there is effort to address them by improving efficiency, reducing waste, using industrial symbiosis, and eliminating harmful chemicals. The negative costs of manufacturing can also be addressed legally, developed countries regulate manufacturing activity with labor laws and environmental laws. Across the globe, manufacturers can be subject to regulations and pollution taxes to offset the costs of manufacturing activities. Labor unions and craft guilds have played a role in the negotiation of worker rights. Environment laws and labor protections that are available in developed nations may not be available in the third world, tort law and product liability impose additional costs on manufacturing
10.
Incandescent light bulb
–
An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated to such a high temperature that it glows with visible light. The filament, heated by passing a current through it, is protected from oxidation with a glass or quartz bulb that is filled with inert gas or evacuated. In a halogen lamp, filament evaporation is prevented by a process that redeposits metal vapor onto the filament. The light bulb is supplied with current by feed-through terminals or wires embedded in the glass. Most bulbs are used in a socket which provides mechanical support, Incandescent bulbs are manufactured in a wide range of sizes, light output, and voltage ratings, from 1.5 volts to about 300 volts. They require no external regulating equipment, have low manufacturing costs, the remaining energy is converted into heat. The luminous efficacy of an incandescent bulb is 16 lumens per watt. Some applications of the incandescent bulb deliberately use the heat generated by the filament, such applications include incubators, brooding boxes for poultry, heat lights for reptile tanks, infrared heating for industrial heating and drying processes, lava lamps, and the Easy-Bake Oven toy. In addressing the question of who invented the incandescent lamp, historians Robert Friedel and Paul Israel list 22 inventors of incandescent lamps prior to Joseph Swan, historian Thomas Hughes has attributed Edisons success to his development of an entire, integrated system of electric lighting. In 1761 Ebenezer Kinnersley demonstrated heating a wire to incandescence and it was not bright enough nor did it last long enough to be practical, but it was the precedent behind the efforts of scores of experimenters over the next 75 years. Over the first three-quarters of the 19th century many experimenters worked with various combinations of platinum or iridium wires, carbon rods, many of these devices were demonstrated and some were patented. In 1835, James Bowman Lindsay demonstrated a constant electric light at a meeting in Dundee. He stated that he could read a book at a distance of one, however, having perfected the device to his own satisfaction, he turned to the problem of wireless telegraphy and did not develop the electric light any further. His claims are not well documented, although he is credited in Challoner et al. with being the inventor of the Incandescent Light Bulb, in 1838, Belgian lithographer Marcellin Jobard invented an incandescent light bulb with a vacuum atmosphere using a carbon filament. In 1840, British scientist Warren de la Rue enclosed a coiled platinum filament in a vacuum tube, although a workable design, the cost of the platinum made it impractical for commercial use. In 1841, Frederick de Moleyns of England was granted the first patent for an incandescent lamp, in 1845, American John W. Starr acquired a patent for his incandescent light bulb involving the use of carbon filaments. He died shortly after obtaining the patent, and his invention was never produced commercially, little else is known about him. In 1851, Jean Eugène Robert-Houdin publicly demonstrated incandescent light bulbs on his estate in Blois and his light bulbs are on display in the museum of the Château de Blois
11.
Krypton
–
Krypton is a chemical element with symbol Kr and atomic number 36. It is a member of group 18 elements, a colorless, odorless, tasteless noble gas, krypton occurs in trace amounts in the atmosphere and is often used with other rare gases in fluorescent lamps. With rare exceptions, krypton is chemically inert, Krypton, like the other noble gases, is used in lighting and photography. Krypton light has many spectral lines, and krypton plasma is useful in bright, high-powered gas lasers, Krypton fluoride also makes a useful laser. Krypton was discovered in Britain in 1898 by Sir William Ramsay, a Scottish chemist, and Morris Travers, neon was discovered by a similar procedure by the same workers just a few weeks later. William Ramsay was awarded the 1904 Nobel Prize in Chemistry for discovery of a series of noble gases, in 1960, the International Conference on Weights and Measures defined the meter as 1,650,763.73 wavelengths of light emitted by the krypton-86 isotope. This agreement replaced the 1889 international prototype meter located in Paris and this also obsoleted the 1927 definition of the ångström based on the red cadmium spectral line, replacing it with 1 Å = 10−10 m. The krypton-86 definition lasted until the October 1983 conference, which redefined the meter as the distance light travels in a vacuum during 1/299,792,458 s. Krypton is characterized by several sharp emission lines the strongest being green, Krypton is one of the products of uranium fission. Solid krypton is white and has a cubic crystal structure. Naturally occurring krypton in Earths atmosphere is composed of six stable isotopes, in addition, about thirty unstable isotopes and isomers are known. 81Kr, the product of reactions, is produced with the other naturally occurring isotopes of krypton. Being radioactive, it has a half-life of 230,000 years, Krypton is highly volatile and does not stay in solution in near-surface water, but 81Kr has been used for dating old groundwater. 85Kr is a radioactive noble gas with a half-life of 10.76 years. It is produced by the fission of uranium and plutonium, such as in nuclear bomb testing, 85Kr is released during the reprocessing of fuel rods from nuclear reactors. Concentrations at the North Pole are 30% higher than at the South Pole due to convective mixing, like the other noble gases, krypton is highly chemically unreactive. In fact, before the 1960s, no noble gas compounds had been synthesized, however, following the first successful synthesis of xenon compounds in 1962, synthesis of krypton difluoride was reported in 1963. In the same year, KrF4 was reported by Grosse, there are also unverified reports of a barium salt of a krypton oxoacid
_Hungarian_physicist.jpg)
