Tegal Regency is one of the regencies located in the northwest part of Central Java province of Indonesia, with an area of 876,10 km2. The administrative center used to be in Tegal City, located in the northwest corner of the regency, but Tegal City was administratively separated from the regency and formed into its own territory; the city was replaced as the administrative center of Tegal Regency by Slawi Town, a suburb located about 20 km to the south of the city and within the district boundary. The name of Tegal comes from the word Tetegal which means fertile soil capable of producing agricultural crops. Another source states, Tegal name is believed to come from the word Teteguall; the name given by a trader from Portugal named Tome Pires who stopped at the Port of Tegal in the 1500s. Tegal regency was established on 18 May 1601 when Ki Gede Sebayu was appointed as a Juru Demung in Tegal by the Sultan of Mataram, began to build this area; the northern part of Tegal Regency is lowland. While in the southern part is a mountain, Mount Slamet, rising to a peak of 3,428 m2.
At the border with Pemalang Regency, there are a series of steep hills down which large rivers flow, namely Kali Gung and Kali Erang, both of which are water-eyed upstream of Mount Slamet. Tegal Regency is located in the northwest part of Central Java province, with geographical location 108° 57' 06" - 109° 21' 30" E and 6° 02' 41" - 7° 15' 30" S. Tegal Regency has a strategic location that are in the road of Semarang - Tegal - Cirebon and Semarang - Tegal - Purwokerto - Cilacap, with port facilities located in Tegal City; the boundaries of Tegal Regency are as follows: Administratively, Tegal Regency is divided into 18 districts, which are sub-divided into 281 villages and 6 urban villages. Since its establishment, the administrative center of Tegal Regency is located in Tegal City. However, since the issuance of Government Regulation No. 2/1984, its administrative center was moved from the Tegal City area to Slawi. Beginning in late 1989, Slawi was developed into the capital of Tegal Regency.
The districts and villages / urban villages in Tegal Regency are: From Mataram era to Dutch East Indies era. Ki Gede Sebayu is level with Regent Buried in Balapulang District. Ki Gede Honggowono is level with Regent Buried in Dukuhwaru district. Prince Duke Arya Martoloyo "The First Duke of Tegal". Tumenggung Sindurejo aka Pranantaka aka Gendowor. Tumenggung Honggowono aka Duke Reksonegoro I. Tumenggung Secowijoyo. Tumenggung Secomenggolo. Raden Mas Tumenggung Tritonoto. Tumenggung Bodroyudho Secowardoyo I aka Duke Reksonegoro II. Tumenggung Bodroyudho Secowardoyo II aka Duke Reksonegoro III Buried in Kalisoka Village, Dukuhwaru district. Tumenggung Kartoyudho aka Duke Reksonegoro IV. Raden Mas Panji Haji Cokronegoro IV Buried in Kedungbanteng district. Tumenggung Surenggono Died after being appointed as Tumenggung. Tumenggung Surodiwongso aka Tumenggung Suronegoro. Tumenggung Secomenggolo. Raden Mas Arya Haji Reksonegoro VI. Tumenggung Sosronegoro. Raden Mas Ronggo Surodipuro. Raden Tumenggung Widyoningrat.
R. Tumenggung Panji Sosrokusumo. R. M. Ore. R. M. Kis Buried In Adiwerna District. R. M. Suyitno. R. M. Susmono. J. Patih R. Subiyanto. R. Tumenggung Slamet Kertonegoro. From the Japanese colonial era to the Old Order era, the New Order era and the Reformation era. Mr. Moh. Great Mertokusumo. Raden Sunaryo. Kyai Abu Sujai "As the First Ulama, Talang District. Prawoto Sudibyo R. Soeputro R. M. Susmono Reksonegoro R. M. Sumindro R. M. Projosumarto Sutoro Munadi R. Sutarjo Col. R. Soepadhi Joedodarmo Lieutenant Colonel. R. Samino Sastrosuwignyo Drs. Herman Sumarmo Hasyim Dirjosubroto Drs. H. Wienachto Drs. Sudiatno Drs. H. Soetjipto Drs. Setiawan Sadono Drs. H. Soediharto Agus Riyanto, S. Sos, M. M. H. M. Heri Soelistiawan, S. H. M. Hum. Drs. Haron Bagas Prakosa, M. Hum. Ir. Satriyo Widodo Ki Enthus Susmono, Ph. D. Tegal Regency is the 21st most densely populated regency in Central Java based on the 2016 official estimates; the main population distribution is southern of Tegal City and along Tegal - Slawi Highway. In daily life, the people of Tegal Regency use Banyumasan-Javanese Language with Tegalese dialect, now known as Tegalese Language.
Home IndustryThe people of Tegal Regency have many businesses in the home industry sector, including casting, textile, shuttlecock and pottery. There are industrial plants of chalk and powder raw materials in the area of Margasari District as the main supplier of powder in Tegal Regency. Agriculture and PlantationThe people of Tegal Regency work in agriculture and plantation sectors in the southern part of Tegal regency in the district of Bumijawa and Bojong. The
A royal charter is a formal grant issued by a monarch under royal prerogative as letters patent. They have been used to promulgate public laws, the most famous example being the British Magna Carta of 1215, but since the 14th century have only been used in place of private acts to grant a right or power to an individual or a body corporate, they were, are still, used to establish significant organisations such as boroughs and learned societies. Charters should be distinguished from royal warrants of appointment, grants of arms and other forms of letters patent, such as those granting an organisation the right to use the word "royal" in their name or granting city status, which do not have legislative effect; the British monarchy has issued over 1,000 royal charters. Of these about 750 remain in existence; the earliest charter recorded by the UK government was granted to the University of Cambridge in England in 1231, although older charters are known to have existed including to the Worshipful Company of Weavers in England in 1150 and to the town of Tain in Scotland in 1066.
Charters continue to be issued by the British Crown, a recent example being that awarded to The Chartered Institute of Ergonomics and Human Factors, in 2014. Charters have been used in Europe since medieval times to grant rights and privileges to towns and cities. During the 14th and 15th century the concept of incorporation of a municipality by royal charter evolved. Among the past and present groups formed by royal charter are the Company of Merchants of the Staple of England, the British East India Company, the Hudson's Bay Company, the Chartered Bank of India and China, the Peninsular and Oriental Steam Navigation Company, the British South Africa Company, some of the former British colonies on the North American mainland, City livery companies, the Bank of England and the British Broadcasting Corporation. Between the 14th and 19th centuries, royal charters were used to create chartered companies – for-profit ventures with shareholders, used for exploration and colonisation. Early charters to such companies granted trade monopolies, but this power was restricted to parliament from the end of the 17th century.
Until the 19th century, royal charters were the only means other than an act of parliament by which a company could be incorporated. The use of royal charters to incorporate organisations gave rise to the concept of the "corporation by prescription"; this enabled corporations that had existed from time immemorial to be recognised as incorporated via the legal fiction of a "lost charter". Examples of corporations by prescription include Cambridge universities. According to the Catholic Encyclopedia, of the 81 universities established in pre-Reformation Europe, 13 were established ex consuetudine without any form of charter, 33 by Papal bull alone, 20 by both Papal bull and imperial or royal charter, 15 by imperial or royal charter alone. Universities established by royal charter did not have the same international recognition – their degrees were only valid within that kingdom; the first university to be founded by charter was the University of Naples in 1224, founded by an imperial charter of Frederick II.
The first university founded by royal charter was the University of Coimbra in 1290, by King Denis of Portugal, which received Papal confirmation the same year. Other early universities founded by royal charter include the University of Perpignan and the University of Huesca, both by Peter IV of Aragon, the Jagiellonian University by Casimir III of Poland, the University of Vienna by Rudolf IV, Duke of Austria, the University of Caen by Henry VI of England, the University of Girona and the University of Barcelona, both by Alfonso V of Aragon, the University of Valence by the Dauphin Louis, the University of Palma by Ferdinand II of Aragon; the University of Cambridge was confirmed by a Papal bull in 1317 or 1318, but despite repeated attempts, the University of Oxford never received such confirmation. The three pre-Reformation Scottish universities were all established by Papal bulls. Following the reformation, establishment of universities and colleges by royal charter became the norm; the University of Edinburgh was founded under the authority of a royal charter granted to the Edinburgh town council in 1582 by James VI as the "town's college".
Trinity College Dublin was established by a royal charter of Elizabeth I in 1593. Both of these charters were given in Latin; the Edinburgh charter gave permission for the town council "to build and to repair sufficient houses and places for the reception and teaching of professors of the schools of grammar, the humanities and languages, theology and law, or whichever liberal arts which we declare detract in no way from the aforesaid mortification" and granted them the right to appoint and remove professors. But, as concluded by Edinburgh's principal, Sir Alexander Grant, in his tercentenary history of the university, "Obviously this is no charter founding a university". Instead
Zwolle is a city and municipality in the northeastern Netherlands serving as Overijssel's capital. With a population of 125,806, it is the second-largest municipality of the province after Enschede. Archaeological findings indicate that the area surrounding Zwolle has been inhabited for a long time. A woodhenge, found in the Zwolle-Zuid suburb in 1993 was dated to the Bronze Age period. During the Roman era, the area was inhabited by Salian Franks; the modern city was founded around 800 CE by Frisian troops of Charlemagne. The name Zwolle is derived from the word Suolle, which means "hill"; this refers to an incline in the landscape between the four rivers surrounding the city, IJssel, Vecht, Aa and Zwarte Water. The hill was the only piece of land that would remain dry during the frequent floodings of the rivers. Zwolle was established on that incline. A document mentions the existence of a parish church dedicated to St Michael; that church, the Grote or Sint Michaëlskerk, was renovated in the first half of the 15th century and exists to this day.
The church contains a richly carved pulpit, the work of Adam Straes van Weilborch, some good carving and an exquisite organ. On August 31, 1230, the bishop of Utrecht granted Zwolle city rights. Zwolle became a member of the Hanseatic league in 1294, in 1361 joined the war between the Hanseatic League and Valdemar IV of Denmark. In the 1370 Treaty of Stralsund that ended the war, Zwolle was awarded a vitte, a trade colony, in Scania part of Denmark. Zwolle's golden age came in the 15th century. Between 1402 and 1450, the city's Gross Regional Product multiplied by about six. In July 1324 and October 1361, regional noblemen set fire to Zwolle. In the 1324 fire, only nine buildings escaped the flames. Zwolle was with Deventer, one of the centers of the Brethren of the Common Life, a monastic movement. 5 km from Zwolle, on a slight eminence called the Agnietenberg, once stood the Augustinian convent in which Thomas à Kempis spent the greatest part of his life and died. At least as early as 1911, Zwolle had a considerable trade by river, a large fish market, the most important cattle market in the Netherlands after Rotterdam.
The more important industries comprised cotton manufactures, iron works, boat-building and bleaching, rope-making, salt-making. In World War II, Zwolle was single-handedly liberated from the Germans by French Canadian soldier Léo Major, he was made an honorary citizen of Zwolle in 2005 and a street is named for him. In 2004, Zwolle's De Librije restaurant was honored with 3 stars by Michelin Guide. Citizens of Zwolle are colloquially known as Blauwvingers; this dates back to 1682. The authorities were strapped for cash and saw no option but to sell the church bells to neighbouring city Kampen. To make sure that Kampen would not make too much profit from the deal, the local authorities asked a high price for the church bells. Kampen accepted, yet after the arrival of the bells it became clear, they were too damaged to be played. In revenge, Kampen paid in copper coins of four duiten. Zwolle distrusted Kampen and wanted to be sure they paid the entire price. After the rigorous counting of this vast amount of money, their fingers had turned blue from the copper.
Besides the Grote or Sint Michaëlskerk, there are several other historic monuments in Zwolle. The Roman Catholic Onze Lieve Vrouwe ten Hemelopneming-basilica dates back to 1399; the church tower, called Peperbus, is one of the tallest and most famous church towers in the Netherlands. The modernized town hall was built in 1448. Mention should be made of the Sassenpoort, the city walls, the Mosterdmakerstoren, a guild-house, the former provincial government offices, a Dominican monastery, on the Melkmarkt, two museums. Museum de Fundatie, the fine art museum of the province of Overijssel, is hosted in the former Justice Hall on Blijmarkt Square. In the western part of the city, west of the railway station, there is a quarter of Art Nouveau buildings, concentrated on Koningin Wilhelminastraat, Prinses Julianastraat, Prins Hendrikstraat; these three-store living houses were built in 1900s by various Dutch architects. Eleven of the buildings are protected by the Dutch government; the Broerenkerk church was part of the Dominican monastery founded in 1465.
The monastery was closed in 1580 and the monks were expelled. From 1640 until 1982 the church was used for Protestant services. After a restoration in 1983-1988 it has been used for cultural events and it is now a bookstore. See People from Zwolle Arts, culture and the mediaHein Boele, Dutch voice of Elmo Jonnie Boer, chef with three Michelin stars Gerard ter Borch, painter Tooske Breugem, television host actress Herman Brood, painter/rock star Eef Brouwers and former head of the Netherlands Government Information Service A. den Doolaard, author Rhijnvis Feith, author Bennie den Haan, actor Marnix Kappers, actor Master I. A. M. of Zwolle, engraver To
In the field of engineering, a chemical engineer is a professional, equipped with the knowledge of chemical engineering, works principally in the chemical industry to convert basic raw materials into a variety of products, deals with the design and operation of plants and equipment. In general, a chemical engineer is one who applies and uses principles of chemical engineering in any of its various practical applications; the president of the Institution of Chemical Engineers said in his presidential address "I believe most of us would be willing to regard Edward Charles Howard as the first chemical engineer of any eminence". Others have suggested Johann Rudolf Glauber for his development of processes for the manufacture of the major industrial acids; the term appeared in print in 1839, though from the context it suggests a person with mechanical engineering knowledge working in the chemical industry. In 1880, George E. Davis wrote in a letter to Chemical News "A Chemical Engineer is a person who possesses chemical and mechanical knowledge, who applies that knowledge to the utilisation, on a manufacturing scale, of chemical action."
He proposed the name Society of Chemical Engineers, for what was in fact constituted as the Society of Chemical Industry. At the first General Meeting of the Society in 1882, some 15 of the 300 members described themselves as chemical engineers, but the Society's formation of a Chemical Engineering Group in 1918 attracted about 400 members. In 1905 a publication called The Chemical Engineer was founded in the US, in 1908 the American Institute of Chemical Engineers was established. In 1924 the Institution of Chemical Engineers adopted the following definition: "A chemical engineer is a professional man experienced in the design and operation of plant and works in which matter undergoes a change of state and composition."As can be seen from the definition, the occupation is not limited to the chemical industry, but more the process industries, or other situations in which complex physical and/or chemical processes are to be managed. The UK journal The Chemical Engineer has a series of biographies available online entitled “Chemical Engineers who Changed the World”, the chemical engineer has been concerned with process engineering, which can be divided into two complementary areas: chemical reaction engineering and separation processes.
The modern discipline of chemical engineering, encompasses much more than just process engineering. Chemical engineers are now engaged in the development and production of a diverse range of products, as well as in commodity and specialty chemicals; these products include high-performance materials needed for aerospace, biomedical, electronic and military applications. Examples include ultra-strong fibers, fabrics and composites for vehicles, bio-compatible materials for implants and prosthetics, gels for medical applications and films with special dielectric, optical or spectroscopic properties for opto-electronic devices. Additionally, chemical engineering is intertwined with biology and biomedical engineering. Many chemical engineers work on biological projects such as understanding biopolymers and mapping the human genome. According to a 2015 salary survey by the AIChE, the median annual salary for a chemical engineer was $127,000. In the UK, the IChemE 2016 Salary Survey reported a median salary of £57,000, with a starting salary for a graduate averaging £28,350.
Chemical engineering in the USA is one of the engineering disciplines with the highest participation of women, with 35% of students compared with 20% in engineering. In the UK in 2014, students starting degrees were 25% female, compared with 15% in engineering. US graduates who responded to a 2015 salary survey were 18.8% female. American Institute of Chemical Engineers Distillation Fluid dynamics Heat transfer History of chemical engineering Institution of Chemical Engineers List of chemical engineering societies List of chemical engineers Mass transfer Process control Process design Process engineering Process miniaturization Unit operations Chemfluence American Institute of Chemical Engineers Institution of Chemical Engineers Canadian Society for Chemical Engineers Engineers Australia
Crystal growth is the process where a pre-existing crystal becomes larger as more molecules or ions add in their positions in the crystal lattice or a solution is developed into a crystal and further growth is processed. A crystal is defined as being atoms, molecules, or ions arranged in an orderly repeating pattern, a crystal lattice, extending in all three spatial dimensions. So crystal growth differs from growth of a liquid droplet in that during growth the molecules or ions must fall into the correct lattice positions in order for a well-ordered crystal to grow; the schematic shows a simple example of a crystal with a simple cubic lattice growing by the addition of one additional molecule. When the molecules or ions fall into the positions different from those in a perfect crystal lattice, crystal defects are formed; the molecules or ions in a crystal lattice are trapped in the sense that they cannot move from their positions, so crystal growth is irreversible, as once the molecules or ions have fallen into place in the growing lattice, they are fixed in place.
Crystallization is a common process, both in industry and in the natural world, crystallization is understood as consisting of two processes. If there is no pre-existing crystal a new crystal must nucleate, this crystal must undergo crystal growth; the interface between a crystal and its vapor can be molecularly sharp at temperatures well below the melting point. An ideal crystalline surface grows by the spreading of single layers, or equivalently, by the lateral advance of the growth steps bounding the layers. For perceptible growth rates, this mechanism requires a finite driving force in order to lower the nucleation barrier sufficiently for nucleation to occur by means of thermal fluctuations. In the theory of crystal growth from the melt and Cabrera have distinguished between two major mechanisms: The surface advances by the lateral motion of steps which are one interplanar spacing in height. An element of surface undergoes no change and does not advance normal to itself except during the passage of a step, it advances by the step height.
It is useful to consider the step as the transition between two adjacent regions of a surface which are parallel to each other and thus identical in configuration — displaced from each other by an integral number of lattice planes. Note here the distinct possibility of a step in a diffuse surface though the step height would be much smaller than the thickness of the diffuse surface; the surface advances normal to itself without the necessity of a stepwise growth mechanism. This means that in the presence of a sufficient thermodynamic driving force, every element of surface is capable of a continuous change contributing to the advancement of the interface. For a sharp or discontinuous surface, this continuous change may be more or less uniform over large areas each successive new layer. For a more diffuse surface, a continuous growth mechanism may require change over several successive layers simultaneously. Non-uniform lateral growth is a geometrical motion of steps — as opposed to motion of the entire surface normal to itself.
Alternatively, uniform normal growth is based on the time sequence of an element of surface. In this mode, there is no change except when a step passes via a continual change; the prediction of which mechanism will be operative under any set of given conditions is fundamental to the understanding of crystal growth. Two criteria have been used to make this prediction: Whether or not the surface is diffuse: a diffuse surface is one in which the change from one phase to another is continuous, occurring over several atomic planes; this is in contrast to a sharp surface for which the major change in property is discontinuous, is confined to a depth of one interplanar distance. Whether or not the surface is singular: a singular surface is one in which the surface tension as a function of orientation has a pointed minimum. Growth of singular surfaces is known to requires steps, whereas it is held that non-singular surfaces can continuously advance normal to themselves. Consider next the necessary requirements for the appearance of lateral growth.
It is evident that the lateral growth mechanism will be found when any area in the surface can reach a metastable equilibrium in the presence of a driving force. It will tend to remain in such an equilibrium configuration until the passage of a step. Afterward, the configuration will be identical except that each part of the step but will have advanced by the step height. If the surface cannot reach equilibrium in the presence of a driving force it will continue to advance without waiting for the lateral motion of steps. Thus, Cahn concluded that the distinguishing feature is the ability of the surface to reach an equilibrium state in the presence of the driving force, he concluded that for every surface or interface in a crystalline medium, there exists a critical driving force, which, if exceeded, will enable the surface or interface to advance normal to itself, and, if not exceeded, will require the lateral growth mechanism. Thus, for sufficiently large driving forces, the interface can move uniformly without the benefit of either a heterogeneous nucleation or screw dislocation mechanism.
What constitutes a sufficiently large driving force depends upon the diffuseness of the interface, so that for diffuse interfaces, this critical driving force will be so small that any measurable driving force will exceed it. Alternatively, for sharp interfaces, the critical driving force will be large, most growth will occur by the lateral step mechanism. Note that in a typical solidification or crystall
Chemistry education is the study of the teaching and learning of chemistry in all schools and universities. Topics in chemistry education might include understanding how students learn chemistry, how best to teach chemistry, how to improve learning outcomes by changing teaching methods and appropriate training of chemistry instructors, within many modes, including classroom lecture and laboratory activities. There is a constant need to update the skills of teachers engaged in teaching chemistry, so chemistry education speaks to this need. There are at least four different philosophical perspectives that describe how the work in chemistry education is carried out; the first is what one might call a practitioner’s perspective, wherein the individuals who are responsible for teaching chemistry are the ones who define chemistry education by their actions. A second perspective is defined by a self-identified group of chemical educators, faculty members and instructors who, as opposed to declaring their primary interest in a typical area of laboratory research, take on an interest in contributing suggestions, essays and other descriptive reports of practice into the public domain, through journal publications and presentations.
Dr. Robert L. Lichter, then-Executive Director of the Camille and Henry Dreyfus Foundation, speaking in a plenary session at the 16th Biennial Conference on Chemical Education, posed the question “why do terms like ‘chemical educator’ exist in higher education, when there is a respectable term for this activity, namely, ‘chemistry professor.’ One criticism of this view is that few professors bring any formal preparation in or background about education to their jobs, so lack any professional perspective on the teaching and learning enterprise discoveries made about effective teaching and how students learn. A third perspective is chemical education research. Following the example of physics education research, CER tends to take the theories and methods developed in pre-college science education research, which takes place in Schools of Education, applies them to understanding comparable problems in post-secondary settings. Like science education researchers, CER practitioners tend to study the teaching practices of others as opposed to focusing on their own classroom practices.
Chemical education research is carried out in situ using human subjects from secondary and post-secondary schools. Chemical education research utilizes both qualitative data collection methods. Quantitative methods involve collecting data that can be analyzed using various statistical methods. Qualitative methods include interviews, observations and other methods common to social science research. There is an emergent perspective called The Scholarship of Teaching and Learning. Although there is debate on how to best define SoTL, one of the primary practices is for mainstream faculty members to develop a more informed view of their practices, how to carry out research and reflection on their own teaching, about what constitutes deep understanding in student learning. Chemistry courses are required for many university students for students who are studying science; some students find chemistry classes and lab work stressful. This anxiety has been called chemophobia. Fears center on academic performance, the difficulty of learning chemical equations, fear of getting lab chemicals on the hands.
Women students were more anxious than men. Previous exposure to learning chemistry was associated with lower anxiety. See chemophobia for aversion to chemical compounds rather than chemistry as a subject in education. There are many journals where papers related to chemistry education can be published; the circulation of many of these journals was limited to the country of publication. Some concentrate on chemistry at different education levels. Most of these journals carry a mixture of articles that range from reports on classroom and laboratory practices to educational research. Australian Journal of Education in Chemistry: Published by the Royal Australian Chemical Institute and covering both School and University education. Chemistry Education Research and Practice: Published by the Royal Society of Chemistry CERP publishes research concerned with all aspects of chemistry education. CERP publishes theoretical perspectives, literature reviews, empirical papers, including systematic evaluations of innovative practice.
Education in Chemistry: Published by the Royal Society of Chemistry with a coverage of all areas of chemical education. EiC is the RSC's educational magazine. Foundations of Chemistry: Published by Springer]] with a coverage of philosophical and historical aspects of chemical education. Journal of Chemical Education: Published by the Chemical Education Division of the American Chemical Society and covering both School and University education, it was established in 1924. The Chemical Educator: Coverage of all areas of chemical education. Chemical Education Journal: Coverage of all areas of chemical education. List of scientific journals in chemistryMuch research in chemistry education is pub
Chemistry is the scientific discipline involved with elements and compounds composed of atoms and ions: their composition, properties and the changes they undergo during a reaction with other substances. In the scope of its subject, chemistry occupies an intermediate position between physics and biology, it is sometimes called the central science because it provides a foundation for understanding both basic and applied scientific disciplines at a fundamental level. For example, chemistry explains aspects of plant chemistry, the formation of igneous rocks, how atmospheric ozone is formed and how environmental pollutants are degraded, the properties of the soil on the moon, how medications work, how to collect DNA evidence at a crime scene. Chemistry addresses topics such as how atoms and molecules interact via chemical bonds to form new chemical compounds. There are four types of chemical bonds: covalent bonds, in which compounds share one or more electron; the word chemistry comes from alchemy, which referred to an earlier set of practices that encompassed elements of chemistry, philosophy, astronomy and medicine.
It is seen as linked to the quest to turn lead or another common starting material into gold, though in ancient times the study encompassed many of the questions of modern chemistry being defined as the study of the composition of waters, growth, disembodying, drawing the spirits from bodies and bonding the spirits within bodies by the early 4th century Greek-Egyptian alchemist Zosimos. An alchemist was called a'chemist' in popular speech, the suffix "-ry" was added to this to describe the art of the chemist as "chemistry"; the modern word alchemy in turn is derived from the Arabic word al-kīmīā. In origin, the term is borrowed from the Greek χημία or χημεία; this may have Egyptian origins since al-kīmīā is derived from the Greek χημία, in turn derived from the word Kemet, the ancient name of Egypt in the Egyptian language. Alternately, al-kīmīā may derive from χημεία, meaning "cast together"; the current model of atomic structure is the quantum mechanical model. Traditional chemistry starts with the study of elementary particles, molecules, metals and other aggregates of matter.
This matter can be studied in isolation or in combination. The interactions and transformations that are studied in chemistry are the result of interactions between atoms, leading to rearrangements of the chemical bonds which hold atoms together; such behaviors are studied in a chemistry laboratory. The chemistry laboratory stereotypically uses various forms of laboratory glassware; however glassware is not central to chemistry, a great deal of experimental chemistry is done without it. A chemical reaction is a transformation of some substances into one or more different substances; the basis of such a chemical transformation is the rearrangement of electrons in the chemical bonds between atoms. It can be symbolically depicted through a chemical equation, which involves atoms as subjects; the number of atoms on the left and the right in the equation for a chemical transformation is equal. The type of chemical reactions a substance may undergo and the energy changes that may accompany it are constrained by certain basic rules, known as chemical laws.
Energy and entropy considerations are invariably important in all chemical studies. Chemical substances are classified in terms of their structure, phase, as well as their chemical compositions, they can be analyzed using the tools of e.g. spectroscopy and chromatography. Scientists engaged in chemical research are known as chemists. Most chemists specialize in one or more sub-disciplines. Several concepts are essential for the study of chemistry; the particles that make up matter have rest mass as well – not all particles have rest mass, such as the photon. Matter can be a mixture of substances; the atom is the basic unit of chemistry. It consists of a dense core called the atomic nucleus surrounded by a space occupied by an electron cloud; the nucleus is made up of positively charged protons and uncharged neutrons, while the electron cloud consists of negatively charged electrons which orbit the nucleus. In a neutral atom, the negatively charged electrons balance out the positive charge of the protons.
The nucleus is dense. The atom is the smallest entity that can be envisaged to retain the chemical properties of the element, such as electronegativity, ionization potential, preferred oxidation state, coordination number, preferred types of bonds to form. A chemical element is a pure substance, composed of a single type of atom, characterized by its particular number of protons in the nuclei of its atoms, known as the atomic number and represented by the symbol Z; the mass number is the sum of the number of neutrons in a nucleus. Although all the nuclei of all atoms belonging to one element will have the same