1.
Scientist
–
A scientist is a person engaging in a systematic activity to acquire knowledge that describes and predicts the natural world. In a more restricted sense, a scientist may refer to an individual who uses the scientific method, the person may be an expert in one or more areas of science. The term scientist was coined by the theologian, philosopher and historian of science William Whewell and this article focuses on the more restricted use of the word. Scientists perform research toward a comprehensive understanding of nature, including physical, mathematical and social realms. Philosophers aim to provide an understanding of fundamental aspects of reality and experience, often pursuing inquiries with conceptual, rather than empirical. When science is done with a goal toward practical utility, it is called applied science, an applied scientist may not be designing something in particular, but rather is conducting research with the aim of developing new technologies and practical methods. When science seeks to answer questions about aspects of reality it is sometimes called natural philosophy. Science and technology have continually modified human existence through the engineering process, as a profession the scientist of today is widely recognized. Jurisprudence and mathematics are often grouped with the sciences, some of the greatest physicists have also been creative mathematicians and lawyers. There is a continuum from the most theoretical to the most empirical scientists with no distinct boundaries, in terms of personality, interests, training and professional activity, there is little difference between applied mathematicians and theoretical physicists. Scientists can be motivated in several ways, many have a desire to understand why the world is as we see it and how it came to be. They exhibit a strong curiosity about reality, other motivations are recognition by their peers and prestige, or the desire to apply scientific knowledge for the benefit of peoples health, the nations, the world, nature or industries. Scientists tend to be motivated by direct financial reward for their work than other careers. As a result, scientific researchers often accept lower average salaries when compared with other professions which require a similar amount of training. The number of scientists is vastly different from country to country, for instance, there are only 4 full-time scientists per 10,000 workers in India while this number is 79 for the United Kingdom and the United States. According to the US National Science Foundation 4.7 million people with science degrees worked in the United States in 2015, across all disciplines, the figure included twice as many men as women. Of that total, 17% worked in academia, that is, at universities and undergraduate institutions, 5% of scientists worked for the federal government and about 3. 5% were self-employed. Of the latter two groups, two-thirds were men, 59% of US scientists were employed in industry or business, and another 6% worked in non-profit positions
2.
Chemistry
–
Chemistry is a branch of physical science that studies the composition, structure, properties and change of matter. Chemistry is sometimes called the science because it bridges other natural sciences, including physics. For the differences between chemistry and physics see comparison of chemistry and physics, the history of chemistry can be traced to alchemy, which had been practiced for several millennia in various parts of the world. The word chemistry comes from alchemy, which referred to a set of practices that encompassed elements of chemistry, metallurgy, philosophy, astrology, astronomy, mysticism. An alchemist was called a chemist in popular speech, and later 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 and this may have Egyptian origins since al-kīmīā is derived from the Greek χημία, which is in turn derived from the word Chemi or Kimi, which is the ancient name of Egypt in Egyptian. Alternately, al-kīmīā may derive from χημεία, meaning cast together, in retrospect, the definition of chemistry has changed over time, as new discoveries and theories add to the functionality of the science. The term chymistry, in the view of noted scientist Robert Boyle in 1661, in 1837, Jean-Baptiste Dumas considered the word chemistry to refer to the science concerned with the laws and effects of molecular forces. More recently, in 1998, Professor Raymond Chang broadened the definition of chemistry to mean the study of matter, early civilizations, such as the Egyptians Babylonians, Indians amassed practical knowledge concerning the arts of metallurgy, pottery and dyes, but didnt develop a systematic theory. Greek atomism dates back to 440 BC, arising in works by such as Democritus and Epicurus. In 50 BC, the Roman philosopher Lucretius expanded upon the theory in his book De rerum natura, unlike modern concepts of science, Greek atomism was purely philosophical in nature, with little concern for empirical observations and no concern for chemical experiments. Work, particularly the development of distillation, continued in the early Byzantine period with the most famous practitioner being the 4th century Greek-Egyptian Zosimos of Panopolis. He formulated Boyles law, rejected the four elements and proposed a mechanistic alternative of atoms. Before his work, though, many important discoveries had been made, the Scottish chemist Joseph Black and the Dutchman J. B. English scientist John Dalton proposed the theory of atoms, that all substances are composed of indivisible atoms of matter. Davy discovered nine new elements including the alkali metals by extracting them from their oxides with electric current, british William Prout first proposed ordering all the elements by their atomic weight as all atoms had a weight that was an exact multiple of the atomic weight of hydrogen. The inert gases, later called the noble gases were discovered by William Ramsay in collaboration with Lord Rayleigh at the end of the century, thereby filling in the basic structure of the table. Organic chemistry was developed by Justus von Liebig and others, following Friedrich Wöhlers synthesis of urea which proved that organisms were, in theory
3.
Chemical reaction
–
A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Nuclear chemistry is a sub-discipline of chemistry that involves the reactions of unstable. The substance initially involved in a reaction are called reactants or reagents. Chemical reactions are characterized by a chemical change, and they yield one or more products. Reactions often consist of a sequence of individual sub-steps, the elementary reactions. Chemical reactions are described with chemical equations, which present the starting materials, end products. Chemical reactions happen at a characteristic reaction rate at a given temperature, typically, reaction rates increase with increasing temperature because there is more thermal energy available to reach the activation energy necessary for breaking bonds between atoms. Reactions may proceed in the forward or reverse direction until they go to completion or reach equilibrium, Reactions that proceed in the forward direction to approach equilibrium are often described as spontaneous, requiring no input of free energy to go forward. Non-spontaneous reactions require input of energy to go forward. Different chemical reactions are used in combinations during chemical synthesis in order to obtain a desired product, in biochemistry, a consecutive series of chemical reactions form metabolic pathways. These reactions are catalyzed by protein enzymes. Chemical reactions such as combustion in fire, fermentation and the reduction of ores to metals were known since antiquity, in the Middle Ages, chemical transformations were studied by Alchemists. They attempted, in particular, to lead into gold, for which purpose they used reactions of lead. The process involved heating of sulfate and nitrate minerals such as sulfate, alum. In the 17th century, Johann Rudolph Glauber produced hydrochloric acid and sodium sulfate by reacting sulfuric acid, further optimization of sulfuric acid technology resulted in the contact process in the 1880s, and the Haber process was developed in 1909–1910 for ammonia synthesis. From the 16th century, researchers including Jan Baptist van Helmont, Robert Boyle, the phlogiston theory was proposed in 1667 by Johann Joachim Becher. It postulated the existence of an element called phlogiston, which was contained within combustible bodies. This proved to be false in 1785 by Antoine Lavoisier who found the explanation of the combustion as reaction with oxygen from the air
4.
Materials science
–
The interdisciplinary field of materials science, also commonly termed materials science and engineering, involves the discovery and design of new materials, with an emphasis on solids. Materials science still incorporates elements of physics, chemistry, and engineering, as such, the field was long considered by academic institutions as a sub-field of these related fields. Materials science is a syncretic discipline hybridizing metallurgy, ceramics, solid-state physics and it is the first example of a new academic discipline emerging by fusion rather than fission. Many of the most pressing scientific problems humans currently face are due to the limits of the materials that are available, thus, breakthroughs in materials science are likely to affect the future of technology significantly. Materials scientists emphasize understanding how the history of a material influences its structure, the understanding of processing-structure-properties relationships is called the § materials paradigm. This paradigm is used to advance understanding in a variety of areas, including nanotechnology, biomaterials. Such investigations are key to understanding, for example, the causes of various accidents and incidents. The material of choice of a given era is often a defining point, phrases such as Stone Age, Bronze Age, Iron Age, and Steel Age are great examples. Originally deriving from the manufacture of ceramics and its putative derivative metallurgy, materials science is one of the oldest forms of engineering, modern materials science evolved directly from metallurgy, which itself evolved from mining and ceramics and the use of fire. Materials science has driven, and been driven by, the development of technologies such as rubbers, plastics, semiconductors. Before the 1960s, many materials science departments were named metallurgy departments, reflecting the 19th, a material is defined as a substance that is intended to be used for certain applications. There are a myriad of materials around us—they can be found in anything from buildings to spacecraft, Materials can generally be divided into two classes, crystalline and non-crystalline. The traditional examples of materials are metals, semiconductors, ceramics, New and advanced materials that are being developed include nanomaterials and biomaterials, etc. The basis of science involves studying the structure of materials. Once a materials scientist knows about this structure-property correlation, they can go on to study the relative performance of a material in a given application. The major determinants of the structure of a material and thus of its properties are its constituent chemical elements and these characteristics, taken together and related through the laws of thermodynamics and kinetics, govern a materials microstructure, and thus its properties. As mentioned above, structure is one of the most important components of the field of materials science, Materials science examines the structure of materials from the atomic scale, all the way up to the macro scale. Characterization is the way materials scientists examine the structure of a material, structure is studied at various levels, as detailed below
5.
Dmitri Mendeleev
–
Dmitri Ivanovich Mendeleev was a Russian chemist and inventor. Mendeleev was born in the village of Verkhnie Aremzyani, near Tobolsk in Siberia, to Ivan Pavlovich Mendeleev and his grandfather was Pavel Maximovich Sokolov, a priest of the Russian Orthodox Church from the Tver region. Ivan, along with his brothers and sisters, obtained new family names while attending the theological seminary, Mendeleev was raised as an Orthodox Christian, his mother encouraging him to patiently search divine and scientific truth. His son would later inform that he departed from the Church, Mendeleev is thought to be the youngest of either 11,13,14 or 17 siblings, the exact number differs among sources. His father was a teacher of arts, politics and philosophy. Unfortunately for the familys financial well being, his father became blind and his mother was forced to work and she restarted her familys abandoned glass factory. At the age of 13, after the passing of his father, in 1849, his mother took Mendeleev across the entire state of Russia from Siberia to Moscow with the aim of getting Mendeleev a higher education. The university in Moscow did not accept him, the mother and son continued to St. Petersburg to the father’s alma mater. The now poor Mendeleev family relocated to Saint Petersburg, where he entered the Main Pedagogical Institute in 1850, after graduation, he contracted tuberculosis, causing him to move to the Crimean Peninsula on the northern coast of the Black Sea in 1855. While there he became a master of the Simferopol gymnasium №1. In 1857, he returned to Saint Petersburg with fully restored health, between 1859 and 1861, he worked on the capillarity of liquids and the workings of the spectroscope in Heidelberg. Later in 1861, he published a textbook named Organic Chemistry and this won him the Demidov Prize of the Petersburg Academy of Sciences. On 4 April 1862 he became engaged to Feozva Nikitichna Leshcheva, Mendeleev became a professor at the Saint Petersburg Technological Institute and Saint Petersburg State University in 1864, and 1865, respectively. In 1865 he became Doctor of Science for his dissertation On the Combinations of Water with Alcohol and he achieved tenure in 1867 at St. Petersburg University and started to teach inorganic chemistry, while succeeding Voskresenskii to this post. And by 1871 he had transformed Saint Petersburg into a recognized center for chemistry research. In 1876, he became obsessed with Anna Ivanova Popova and began courting her, in 1881 he proposed to her and his divorce from Leshcheva was finalized one month after he had married Popova in early 1882. Even after the divorce, Mendeleev was technically a bigamist, the Russian Orthodox Church required at least seven years before lawful remarriage and his divorce and the surrounding controversy contributed to his failure to be admitted to the Russian Academy of Sciences. His daughter from his marriage, Lyubov, became the wife of the famous Russian poet Alexander Blok
6.
Periodic table
–
The periodic table is a tabular arrangement of the chemical elements, ordered by their atomic number, electron configurations, and recurring chemical properties. This ordering shows periodic trends, such as elements with similar behaviour in the same column and it also shows four rectangular blocks with some approximately similar chemical properties. In general, within one row the elements are metals on the left, the rows of the table are called periods, the columns are called groups. Six groups have names as well as numbers, for example, group 17 elements are the halogens, and group 18, the noble gases. The periodic table can be used to derive relationships between the properties of the elements, and predict the properties of new elements yet to be discovered or synthesized, the periodic table provides a useful framework for analyzing chemical behaviour, and is widely used in chemistry and other sciences. The Russian chemist Dmitri Mendeleev published the first widely recognized periodic table in 1869 and he developed his table to illustrate periodic trends in the properties of the then-known elements. Mendeleev also predicted some properties of elements that would be expected to fill gaps in this table. Most of his predictions were proved correct when the elements in question were subsequently discovered, Mendeleevs periodic table has since been expanded and refined with the discovery or synthesis of further new elements and the development of new theoretical models to explain chemical behaviour. The first 94 elements exist naturally, although some are only in trace amounts and were synthesized in laboratories before being found in nature. Elements with atomic numbers from 95 to 118 have only been synthesized in laboratories or nuclear reactors, synthesis of elements having higher atomic numbers is being pursued. Numerous synthetic radionuclides of naturally occurring elements have also produced in laboratories. Each chemical element has an atomic number representing the number of protons in its nucleus. Most elements have differing numbers of neutrons among different atoms, with variants being referred to as isotopes. Isotopes are never separated in the table, they are always grouped together under a single element. Elements with no stable isotopes have the masses of their most stable isotopes. In the standard periodic table, the elements are listed in order of increasing atomic number, a new row is started when a new electron shell has its first electron. Columns are determined by the configuration of the atom, elements with the same number of electrons in a particular subshell fall into the same columns. Thus, it is easy to predict the chemical properties of an element if one knows the properties of the elements around it
7.
Combustion
–
Combustion in a fire produces a flame, and the heat produced can make combustion self-sustaining. Combustion is often a sequence of elementary radical reactions. Solid fuels, such as wood, first undergo endothermic pyrolysis to produce gaseous fuels whose combustion then supplies the required to produce more of them. Combustion is often hot enough that light in the form of either glowing or a flame is produced, a simple example can be seen in the combustion of hydrogen and oxygen into water vapor, a reaction commonly used to fuel rocket engines. The bond energies in the play only a minor role, since they are similar to those in the combustion products. The heat of combustion is approximately -418 kJ per mole of O2 used up in the combustion reaction, uncatalyzed combustion in air requires fairly high temperatures. Complete combustion is stoichiometric with respect to the fuel, where there is no remaining fuel, thermodynamically, the chemical equilibrium of combustion in air is overwhelmingly on the side of the products. Thus, the smoke is usually toxic and contains unburned or partially oxidized products. Since combustion is rarely clean, flue gas cleaning or catalytic converters may be required by law, fires occur naturally, ignited by lightning strikes or by volcanic products. Combustion was the first controlled chemical reaction discovered by humans, in the form of campfires and bonfires, usually, the fuel is carbon, hydrocarbons or more complicated mixtures such as wood that contains partially oxidized hydrocarbons. Combustion is also currently the only used to power rockets. Combustion is also used to destroy waste, both nonhazardous and hazardous, oxidants for combustion have high oxidation potential and include atmospheric or pure oxygen, chlorine, fluorine, chlorine trifluoride, nitrous oxide and nitric acid. For instance, hydrogen burns in chlorine to form hydrogen chloride with the liberation of heat, although usually not catalyzed, combustion can be catalyzed by platinum or vanadium, as in the contact process. In complete combustion, the reactant burns in oxygen, producing a number of products. When a hydrocarbon burns in oxygen, the reaction will yield carbon dioxide. When elements are burned, the products are primarily the most common oxides, carbon will yield carbon dioxide, sulfur will yield sulfur dioxide, and iron will yield iron oxide. Nitrogen is not considered to be a combustible substance when oxygen is the oxidant, Combustion is not necessarily favorable to the maximum degree of oxidation, and it can be temperature-dependent. For example, sulfur trioxide is not produced quantitatively by the combustion of sulfur, NOx species appear in significant amounts above about 2,800 °F, and more is produced at higher temperatures
8.
Fire
–
Fire is the rapid oxidation of a material in the exothermic chemical process of combustion, releasing heat, light, and various reaction products. Slower oxidative processes like rusting or digestion are not included by this definition, at a certain point in the combustion reaction, called the ignition point, flames are produced. The flame is the portion of the fire. Flames consist primarily of carbon dioxide, water vapor, oxygen and nitrogen, if hot enough, the gases may become ionized to produce plasma. Depending on the substances alight, and any impurities outside, the color of the flame, Fire in its most common form can result in conflagration, which has the potential to cause physical damage through burning. Fire is an important process that affects ecological systems around the globe, the positive effects of fire include stimulating growth and maintaining various ecological systems. The negative effects of fire hazard to life and property, atmospheric pollution. If fire removes protective vegetation, heavy rainfall may lead to an increase in soil erosion by water and this is commonly called the fire tetrahedron. Fire cannot exist without all of elements in place and in the right proportions. For example, a liquid will start burning only if the fuel. Some fuel-oxygen mixes may require a catalyst, a substance that is not consumed, when added, in any chemical reaction during combustion, but which enables the reactants to combust more readily. Without gravity, a fire rapidly surrounds itself with its own products and non-oxidizing gases from the air. Because of this, the risk of fire in a spacecraft is small when it is coasting in inertial flight, of course, this does not apply if oxygen is supplied to the fire by some process other than thermal convection. Fire can be extinguished by removing any one of the elements of the fire tetrahedron, consider a natural gas flame, such as from a stovetop burner. In contrast, fire is intensified by increasing the rate of combustion. In many cases, such as the burning of organic matter, for wood, or the incomplete combustion of gas. This light has a continuous spectrum, complete combustion of gas has a dim blue color due to the emission of single-wavelength radiation from various electron transitions in the excited molecules formed in the flame. Usually oxygen is involved, but hydrogen burning in chlorine produces a flame
9.
Iron
–
Iron is a chemical element with symbol Fe and atomic number 26. It is a metal in the first transition series and it is by mass the most common element on Earth, forming much of Earths outer and inner core. It is the fourth most common element in the Earths crust, like the other group 8 elements, ruthenium and osmium, iron exists in a wide range of oxidation states, −2 to +6, although +2 and +3 are the most common. Elemental iron occurs in meteoroids and other low oxygen environments, but is reactive to oxygen, fresh iron surfaces appear lustrous silvery-gray, but oxidize in normal air to give hydrated iron oxides, commonly known as rust. Unlike the metals that form passivating oxide layers, iron oxides occupy more volume than the metal and thus flake off, Iron metal has been used since ancient times, although copper alloys, which have lower melting temperatures, were used even earlier in human history. Pure iron is soft, but is unobtainable by smelting because it is significantly hardened and strengthened by impurities, in particular carbon. A certain proportion of carbon steel, which may be up to 1000 times harder than pure iron. Crude iron metal is produced in blast furnaces, where ore is reduced by coke to pig iron, further refinement with oxygen reduces the carbon content to the correct proportion to make steel. Steels and iron alloys formed with metals are by far the most common industrial metals because they have a great range of desirable properties. Iron chemical compounds have many uses, Iron oxide mixed with aluminium powder can be ignited to create a thermite reaction, used in welding and purifying ores. Iron forms binary compounds with the halogens and the chalcogens, among its organometallic compounds is ferrocene, the first sandwich compound discovered. Iron plays an important role in biology, forming complexes with oxygen in hemoglobin and myoglobin. Iron is also the metal at the site of many important redox enzymes dealing with cellular respiration and oxidation and reduction in plants. A human male of average height has about 4 grams of iron in his body and this iron is distributed throughout the body in hemoglobin, tissues, muscles, bone marrow, blood proteins, enzymes, ferritin, hemosiderin, and transport in plasma. The mechanical properties of iron and its alloys can be evaluated using a variety of tests, including the Brinell test, Rockwell test, the data on iron is so consistent that it is often used to calibrate measurements or to compare tests. An increase in the content will cause a significant increase in the hardness. Maximum hardness of 65 Rc is achieved with a 0. 6% carbon content, because of the softness of iron, it is much easier to work with than its heavier congeners ruthenium and osmium. Because of its significance for planetary cores, the properties of iron at high pressures and temperatures have also been studied extensively
10.
Gold
–
Gold is a chemical element with symbol Au and atomic number 79. In its purest form, it is a bright, slightly yellow, dense, soft, malleable. Chemically, gold is a metal and a group 11 element. It is one of the least reactive chemical elements and is solid under standard conditions, Gold often occurs in free elemental form, as nuggets or grains, in rocks, in veins, and in alluvial deposits. It occurs in a solid solution series with the element silver and also naturally alloyed with copper. Less commonly, it occurs in minerals as gold compounds, often with tellurium, golds atomic number of 79 makes it one of the higher numbered, naturally occurring elements. It is thought to have produced in supernova nucleosynthesis, from the collision of neutron stars. Because the Earth was molten when it was formed, almost all of the present in the early Earth probably sank into the planetary core. Gold is resistant to most acids, though it does dissolve in aqua regia, a mixture of acid and hydrochloric acid. Gold also dissolves in solutions of cyanide, which are used in mining and electroplating. Gold dissolves in mercury, forming amalgam alloys, but this is not a chemical reaction, as a precious metal, gold has been used for coinage, jewelry, and other arts throughout recorded history. A total of 186,700 tonnes of gold is in existence above ground, the world consumption of new gold produced is about 50% in jewelry, 40% in investments, and 10% in industry. Gold is also used in infrared shielding, colored-glass production, gold leafing, certain gold salts are still used as anti-inflammatories in medicine. As of 2014, the worlds largest gold producer by far was China with 450 tonnes, Gold is cognate with similar words in many Germanic languages, deriving via Proto-Germanic *gulþą from Proto-Indo-European *ǵʰelh₃-. The symbol Au is from the Latin, aurum, the Latin word for gold, the Proto-Indo-European ancestor of aurum was *h₂é-h₂us-o-, meaning glow. This word is derived from the root as *h₂éu̯sōs, the ancestor of the Latin word Aurora. This etymological relationship is presumably behind the frequent claim in scientific publications that aurum meant shining dawn, Gold is the most malleable of all metals, a single gram can be beaten into a sheet of 1 square meter, and an avoirdupois ounce into 300 square feet. Gold leaf can be thin enough to become semi-transparent
11.
New Latin
–
New Latin was a revival in the use of Latin in original, scholarly, and scientific works between c.1375 and c. Modern scholarly and technical nomenclature, such as in zoological and botanical taxonomy and international scientific vocabulary, in such use, New Latin is often viewed as still existing and subject to new word formation. As a language for full expression in prose or poetry, however, classicists use the term Neo-Latin to describe the Latin that developed in Renaissance Italy as a result of renewed interest in classical civilization in the 14th and 15th centuries. Neo-Latin also describes the use of the Latin language for any purpose, scientific or literary, during, the term New Latin came into widespread use towards the end of the 1890s among linguists and scientists. New Latin was, at least in its days, an international language used throughout Catholic and Protestant Europe. Russias acquisition of Kiev in the later 17th century introduced the study of Latin to Russia, though Latin and New Latin are considered extinct, large parts of their vocabulary have seeped into English and several Germanic languages. New Latin was inaugurated by the triumph of the humanist reform of Latin education, led by writers as Erasmus, More. Medieval Latin had been the working language of the Roman Catholic Church, taught throughout Europe to aspiring clerics. It was a language, full of neologisms and often composed without reference to the grammar or style of classical authors. Attempts at reforming Latin use occurred sporadically throughout the period, becoming most successful in the mid-to-late 19th century, the Protestant Reformation, though it removed Latin from the liturgies of the churches of Northern Europe, may have advanced the cause of the new secular Latin. Classic works such as Newtons Principia Mathematica were written in the language, throughout this period, Latin was a universal school subject, and indeed, the pre-eminent subject for elementary education in most of Europe and other places of the world that shared its culture. All universities required Latin proficiency to obtain admittance as a student, Latin was an official language of Poland—recognised and widely used between the 9th and 18th centuries, commonly used in foreign relations and popular as a second language among some of the nobility. As an auxiliary language to the local vernaculars, New Latin appeared in a variety of documents, ecclesiastical, legal, diplomatic, academic. As late as the 1720s, Latin was still used conversationally, for instance, the Hanoverian king George I of Great Britain, who had no command of spoken English, communicated in Latin with his Prime Minister Robert Walpole, who knew neither German nor French. By about 1700, the movement for the use of national languages had reached academia, and an example of the transition is Newtons writing career. A much earlier example is Galileo c,1600, some of whose scientific writings were in Latin, some in Italian, the latter to reach a wider audience. Likewise, in the early 18th century, French replaced Latin as a diplomatic language, at the same time, some were dismissing Latin as a useless accomplishment, unfit for a man of practical affairs. The last international treaty to be written in Latin was the Treaty of Vienna in 1738, a diminishing audience combined with diminishing production of Latin texts pushed Latin into a declining spiral from which it has not recovered
