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Adolf von Baeyer (1835-1917) :

Johann Friedrich Wilhelm Adolf von Baeyer was born on October 31, 1835, in Berlin Even as a child Baeyer was interested in chemical experiments and at the age of twelve found a new double salt of copper. In 1865 he started his work on indigo - the blue dye had fascinated him since his youth-and this soon led to the discovery of indole and to the partial synthesis of indigotin. In 1858, in Berlin, he received his doctorate for his work on cacodyl compounds which had been done in Kekulé's laboratory. He gave the famous Baeyer strain theory of the carbon rings based on studies of the constitution of benzene as well as comprehensive investigations into cyclic terpene.He received the noble prize in 1905.

Alfred Bernhard Nobel(1833 – 1896) :

Alfred Bernhard Nobel was a Swedish chemist, engineer, innovator, armaments manufacturer and the inventor of dynamite. He owned Bofors, a major armaments manufacturer, which he had redirected from its previous role as an iron and steel mill. In his last will, he used his enormous fortune to institute the Nobel Prizes. The synthetic element nobelium was named after him. Nobel found that when nitroglycerin was incorporated in an absorbent inert substance like kieselguhr (diatomaceous earth) it became safer and more convenient to handle, and this mixture he patented in 1867 as 'dynamite'. Nobel demonstrated his explosive for the first time that year, at a quarry in Redhill, Surrey, England. Nobel later on combined nitroglycerin with another explosive, gun-cotton, and obtained a transparent, jelly-like substance, which was a more powerful explosive than dynamite. 'Gelignite', or blasting gelatin, as it was named, was patented in 1876; and was followed by a host of similar combinations, modified by the addition of potassium nitrate and various other substances

Antoine-Henri Becquerel (1852-1908) :

Son of Alexandre-Edmond, Antoine-Henri, a civil Engineer was born in Paris, in December 15th 1852, and died, in Croisic, in Britanny, in August 25th 1908. He completed the research work of his father and grandfather, and in 1896 discovered the radioactivity of uranium salts. This important discovery gave him the Nobel Prize in 1903, together with Pierre and Marie Curie.

Antoine Lavoisier (1743-1794) :

Antoine Laurent Lavoisier was born in Paris, in August 26th 1743, and died in May 8th 1794. He is considered the father of the modern Chemistry. Lavoisier completed the work of Priestley and Cavendish, who ended the flogist theory, by correctly interpreting combustions, calcinations and other oxidation reactions and giving rise to the fundamentals of quantitative organic analysis. He named OXYGEN and NITROGEN and popped out with the concept of chemical element. He developed the basis of modern thermodynamics. Lavoisier was secretary and treasurer of a committee appointed in 1790 to determine the standard weights and measures in France, leading to the development of the metric system as it is known now-a-days.

Ampere, André Marie (1775-1836): :

Ampere, a teacher at Paris, has his permanent place in the history of science because it was his name that was given to the unit by which we measure electrical current. He had, of course, an interest in electricity; in addition, Ampere made similar investigations as did Avogadro into the nature of matter in its gaseous state.

Arrhenius, Svante (1859-1927) :

Swedish chemist who explained the electrical conductivity of ionic solutions by presuming that compounds dissociated into oppositely charged ions whose motions constituted a current. This conclusion was supported by observing that the freezing point depression of ionic solids were integer multiples larger than their concentrations would indicate according to Raoult’s Law. He described his theory in his 1884 thesis, which passed the defense with the lowest passing grade. However, it won him the Nobel Prize in chemistry in 1903. He also discovered the Arrhenius Rate Law, which describes the rate at which chemical reactions occur. In Worlds in the Making (1908), he suggested that life on Earth had begun when space-traveling spores reached Earth. He also argued against the ultimate implication of the third law of thermodynamics known as Heat Death.

Avogadro, Armedeo (1776-1856): :

The Italian scientist after which is named the Avogadro's Law, "Equal volumes of different gases, pressure and temperature being equal, contain the same number of molecules"; or, "equal volumes of gases or vapours contain the same number of molecules."

Berthollet, Claude Louis (1748-1822) :

Berthollet studied medicine in Turin (1768). In 1784 he became director of the national Gobelin factories and in 1794 professor of chemistry at the Ecole polytechnique. Berthollet was one of the first chemists to adopt Antoine Lavoisier´s antiphlogistic system. He defended the opinion that the quantitative composition of chemical compounds depends on the relative quantities of the reagents during reactions. His investigations of ammonia and halogen salts were exemplary. He introduced chlorine as bleaching agent. Berthollet was considered one of the leading chemists of his time and was greatly honoured during his lifetime.

Bernoulli, Daniel (1700-82): :

Daniel Bernoulli was a member of a Swiss family that had more than its share of mathematicians and scientists. Daniel studied medicine and mathematics, but, eventually settled into teaching physics at Basel. He proposed the kinetic theory of gases which is known as the Bernoulli’s principle. It might be simply stated, as follows: "as the velocity of a fluid increases, its pressure decreases." Thus it was Daniel Bernoulli who showed that "the total energy in a steadily flowing fluid system is a constant along the flow path. Because the total energy is constant, an increase in the fluid’s speed must therefore be matched by a decrease in its pressure." The Bernoulli’s principle explains why a fixed wing airplane, once it is moving in the air, and, because of the shape of the wing, will (usually) stay in the air. The instrument, in its simplest form, is a tube with a ball in it with the tube (the down side end) being closed and the other being open. When the wind blows over the top of the tube, a slight vacuum is created in the tube and the ball is sucked up. The stronger the wind, the greater the suction and the further up the tube the ball will travel.

Born, Max (1882-1970): :

Max Born was a Jewish-German physicist and mathematician who was instrumental in the development of quantum mechanics. He also made contributions to solid-state physics and optics and supervised the work of a number of notable physicists in the 1920s and 30s. Born won the 1954 Nobel Prize in Physics. In memory of his important contributions, the Max Born prize was created by the German Physical Society and the British Institute of Physics. It is awarded annually.

Brönsted, Johannes Nicolaus (1879-1947) :

Bronsted studied in Copenhagen at the Polytechnic Institute and University, obtained his doctorate in 1908 and was appointed the same year to a newly established professorship in chemistry with teaching courses at both universities. The double duties ended in 1930 when he was given a single professorship with the institute of physical chemistry at the University. Bronsted main achievement was the development of a valid concept of acids and bases in 1923, often referred to as the Bronsted theory of acids and bases. In Bronsted concept, every acid is related to a conjugate base and vice versa. The definition applies to all solvents and not just to water. He also studied activity coefficients introduced by G.N. Lewis and, together with the later Nobel laureate G. Hevesy, the separation of isotopes by molecular distillation. Since 1927 Bronsted became increasingly interested in catalytic effects of acids and bases.

Blaise Pascal ( 1623 -1662) , :

Blaise Pascal was a French mathematician, physicist, and religious philosopher. Pascal's earliest work was in the natural and applied sciences where he made important contributions to the construction of mechanical calculators, the study of fluids, and clarified the concepts of pressure and vacuum by generalizing the work of Evangelista Torricelli. Pascal also wrote in defense of the scientific method. . He wrote a significant treatise on the subject of projective geometry at the age of sixteen, and later corresponded with Pierre de Fermat on probability theory, strongly influencing the development of modern economics and social science. Following Galileo and Torricelli, in 1646 he refuted Aristotle's followers who insisted that nature abhors a vacuum. His results caused many disputes before being accepted.

Charles Martin Hall (1863-1914) :

American metallurgist was born in Thompson, Ohio, in December 6th 1863 and died in Daytona, Florida in December, 27th 1914. In February 23rd, 1886, less than one year after graduation, made the first “nuggets” of aluminum, through the electrolysis of a bauxite solution, in a melted salt. Hall and Paul Louis Toussaint Heroult (a young French metallurgist) together improved the process now known as Hall-Heroult, in which the modern industry of aluminum is based. Hall won the Perkin medal for his discoveries in Applied Chemistry.

Count Alessandro Giuseppe Antonio Anastasio Volta (February 18, 1745 – March 5, 1827) :

Count Alessandro Giuseppe Antonio Anastasio Volta was a physicist known especially for the development of the first electric cell in 1800. In 1775, Volta improved and popularized the electrophorus, a device that produces a static electric charge. In 1776-77 he studied the chemistry of gases, discovered methane, and devised experiments such as the ignition of gases by an electric spark in a closed vessel. Around 1791 he began to study the "animal electricity" noted by Galvani when two different metals were connected in series with the frog's leg and to one another. He realized that the frog's leg served as both a conductor of electricity (we would now call it an electrolyte) and as a detector of electricity. He replaced the frog's leg by brine-soaked paper, and detected the flow of electricity by other means familiar to him from his previous studies of electricity. In this way he discovered the electrochemical series, and the law that the electromotive force (emf) of a galvanic cell, consisting of a pair of metal electrodes separated by electrolyte, is the difference of their two electrode potentials. That is, if the electrodes have emfs , then the net emf is . (Thus, two identical electrodes and a common electrolyte give zero net emf.) This may be called Volta's Law of the electrochemical series.

Charles-Augustin de Coulomb ( 1736 -1806) :

Charles-Augustin de Coulomb was a French physicist. He is best known for developing Coulomb's law, the definition of the electrostatic force of attraction and repulsion. The SI unit of charge, the coulomb, was named after him.

Davy, Sir Humphrey (1778-1829): :

Davy's father was a woodcarver. At a young age, Davy was sent to apprentice with a surgeon in his hometown, Penzance. Such an apprenticeship let Davy to conduct chemical experiments and by nineteen years of age he was carrying out some very serious chemical studies. By age 21 he wrote Researches, Chemical and Philosophical which led to his appointment to the Royal Institution. During the early part of the 19th century, Davy was conducting experiments which led to his conclusions that many common substances were formed by the combination of oxygen and metals. This discovery further led Davy to decompose certain substances, and, in the process was to discover metals not commonly found in their pure state, such metals as: potassium, sodium, barium, strontium, etc. In 1812, Davy was knighted. In 1815, Sir Humphrey invented the safety lamp, his most famous invention, which undoubtedly has saved numerous lives of those who worked in the coal mines. During the last of his years, Sir Humphrey carried out studies in electromagnetism.

Dulong, Pierre Louis (1785-1838): :

The French chemist who, with Petit, became know for the Dulong and Petit's Law (1819), viz., that "all the chemical elements have approximately the same atomic heat"; or, "the same quantity of heat is needed to heat an atom of all simple bodies to the same extent." In 1813, Dulong was to describe the explosive properties of nitrogen trichloride

Dmitri Ivanovitch Mendeleev (1834-1907) :

Russian physicist and chemist, was born in Tobolsk, in Siberia (1834) and died in St.Petersburg (1907). At university of Herdelberg, Germany, he performed a series of researches in spectroscopy together with Kirchhoff and Bunsen, leading to his Ph.D thesis. Performed many research works in chemistry and physics and presented the periodic classification of the elements in 1869

Dumas, Jean Baptiste André (1800-1884) :

As one of the leading chemists of the 19th century Dumas was professor in several institutions in Paris (since 1829). In 1850/51 he was Minister of Agriculture, 1868 he became mintmaster general of France. Among his many papers those on etherin theory, on the theory substitution, on the theory of types, on the measurement of vapour densities and on the determination of nitrogen in organic compounds, on the isolation of anthracene from tar, on chloral, iodoform, bromoform, and on picric acid merit special mention.

Eduard Frankland (1825-1899) :

English chemist and professor was born near Lancaster in January 18th, 1825 and died in Golaa, Norway, in August 9th, 1899. In 1868, he worked in the theory of chemical equivalents, discovered the organometallic compounds and together with Sir Joseph Lockyer, discovered helium in the Sun. In 1850 Frankland announced the preparation of organometallic compounds, such as dimethy-zinc and diethyl-zinc. Posterior studies led this English scientist to the important concept of atomic bonding – the valence theory. He was also a specialist of food chemistry, water analysis, sewer treatment and purification and prevention of water pollution.

Enrico Fermi (1901-1954) :

Enrico Fermi was born in Rome in 1901 and died of cancer in 1954. In 1933, Fermi introduced the concept of weak interaction that, along with the recently postulated neutrino, was used in the theory of the beta decay. Along with a group of co-workers, Fermi began a series of experiences with the purpose of producing artificial radioactive b\nuclei, by bombarding several elements with neutrons. Some of his results suggested the formation of transuranian elements. In fact, these observations, later confirmed by Hahn, were the evidence for nuclear fission. In 1938, Fermi received the Nobel Prize of Physics for this work. The element with atomic number 100, discovered one year after his death, received the name of Fermium, in his honour.

Erwin Schrödinger(1887-1961) :

Erwin Schrödinger was born on August 12, 1887, in Vienna. His papers at that time dealt with specific heats of solids, with problems of thermodynamics (he was greatly interested in Boltzmann's probability theory) and of atomic spectra; in addition, he indulged in physiological studies of colour (as a result of his contacts with Kohlrausch and Exner, and of Helmholtz's lectures). His great discovery, Schrödinger's wave equation, was made at the end of this epoch-during the first half of 1926. It came as a result of his dissatisfaction with the quantum condition in Bohr's orbit theory and his belief that atomic spectra should really be determined by some kind of eigen value problem. For this work he shared with Dirac the Nobel Prize for 1933.

Freiherr Justus von Leibeg (1803-1873) :

Freiherr Justus von Leibeg (1803-1873) was a German chemist who made major contributions to agricultural and biological chemistry, and worked on the organization of organic chemistry. The vapour condensation device he popularized for his research is still known as a Leibeg condenser, although it was in common use long before Liebig's research began. He is known as the "father of the fertilizer industry" for his discovery of nitrogen as an essential plant nutrient. He also invented a process for silvering that greatly improved the utility of mirrors.

Fritz Haber (1868-1934) :

Fritz Haber, a German chemist and a Professor was born in Bresla, in December 9th 1868, and died in Basle, Switzerland, in January 29th, 1934. The research work made by Haber (1905-1911) on the equilibrium between nitrogen, hydrogen and ammonia established the exact temperature and pressure, as well as the catalyst, that optimized the ammonia formation. Ammonia produced through this method could be transformed in nitric acid by oxidation, using the Ostwald process. This acid was then used in producing explosives and fertilizers. He is the winner of the Nobel Prize of Chemistry in 1918, for the synthesis of ammonia from its elements. Haber also worked on the thermodynamics of gaseous reactions, the electrochemistry (especially the electrolytic reduction of nitrobenzene), the composition of flames and explosions of gas, etc.

Gilbert Newton Lewis (1875-1946) :

American chemist and professor, was born in Weymouth, Massachusetts in October 23rd 1875 and died in Berkley, California in March 24th 1946. Lewis is known by his work in thermodynamics, for the Lewis theory for acids and bases and for the development of the valence theory in chemical reactions. In 1916, Lewis proposed that the interaction between two electrons is the base of a valence bonding, an idea developed by Irving Langmuir which remains the base of modern valence theories. Lewis was honoured with the Davy medal by the Royal Society, the Arrhenius medal of the Swedish Academy and the Gibbs and Richards medals.

Gustav Robert Kirchhoff (1824-1887) :

German physicist and professor, was born in Koenigsberg, in 1824 and died in Berlin, in 1887. His more notable scientific works were in the domain of thermal radiation and of spectral analysis, being responsible for the discovery, in 1861, together with Bunsen, of the rubidium and cerium; this work enabled the first explanation of the absorption stripes usually called Fraunhofer stripes.

Grignard, François Auguste Victor (1871-1935) :

Grignard obtained at the faculty of Lyon a licence in mathematics (1894). In the general chemistry laboratory of the Sciences Faculty in Lyon he was able to prepare the so called organomagnesium halides for the synthesis of new organic compounds. Grignard presented his work as his doctor's thesis (1901). Grignard reagents were used in all directions. The usefulness of the device was such that in 1910 he received a professorship in chemistry at the University of Nancy and of Lyon in 1919. In 1912 Grignard shared the Nobel Prize with Sabatier.

Hofmann,August Wilhelm(1818-1892) :

Hofmann was a pupil of Justus Liebig. From 1845 to 1864 he was professor at several institutions in London. After that he served as professor in Bonn and Berlin. His main field of research was organic nitrogen compounds like aniline and toluidine. He became one of the initiators of the coal-tar dyestuff industry. In 1851 he postulated an ammonia type of organic compounds and showed that ammonia salts can be transformed to tertiary amines. Hofmann also produced formaldehyde from methanol and introduced an apparatus for the electrolysis of water.

Henri Gwyn-Jeffreys Moseley (1887-1915) :

English physicist was born in Weimouth in 1887 and died in combat in Dardanelles, Greece in 1915. Performed a systematic study of X-ray spectra, being responsible for the determination of the wavelength of K-alpha of several elements. He also determined the mathematical relation between the radiation wavelength and the atomic numbers of the emitting elements. Pointed out the existence of holes in the periodic table for the elements Z=43, 61, 72 and 75, which were discovered much later.

Henri Louis Le Châtelier (1850-1936) :

French Chemist, Professor and physicist, was born in Paris in October 8th 1850, and died in Miribel-les-Eschelles, Isère, France, in September 17th 1936. In 1884 Le Châtelier enunciated the Law of Mobile Equilibrium, also known as the Le Châtelier principle that states that when an equilibrium system is disturbed, through variation of concentration, pressure, or temperature, the change tries to reduce the immediate effect of that disturbance. Based on this principle, an industry, for example, can foresee in advance the amount of substance necessary to production. Le Châtelier also invented the optical pyrometer, an instrument that measures temperature through the observation bodies color. This instrument is used in ceramics, metallurgy and in oven temperature control.

Henry Cavendish (1731-1810) :

English physicist and chemist was born in Nice, in October 10th 1731, and died, in Clapham, in March 10th 1810. Cavendish is responsible for the first experimental determination of the gravitational constant made with a torsion balance built by him. Based on this work, he calculated the average density of the Earth. Cavendish proved experimentally the electrostatic law of the inverse square and showed that there was no charge remaining in a conductor material after it had been connected to an outer layer conductor. He also worked in Chemistry, identifying hydrogen and determining the composition of the atmosphere.

Sir Henry Bessemer :

Sir Henry Bessemer (January 19, 1813–March 15, 1898), was an English engineer and inventor. Bessemer's name is chiefly known in connection with the Bessemer process for the manufacture of steel. He invented the first process for mass-producing steel inexpensively, essential to the development of skyscrapers. An American, William Kelly, had held a patent for "a system of air blowing the carbon out of pig iron" a method of steel production known as the pneumatic process of steelmaking. Air is blown through molten pig iron to oxidize and remove unwanted impurities. Bankruptcy forced Kelly to sell his patent to Bessemer, who had been working on a similar process for making steel. Bessemer patented "a decarbonization process, utilizing a blast of air" in 1855. Modern steel is made using technology based on Bessemer's process. Bessemer was knighted in 1879 for his contribution to science. The "Bessemer Process" for mass-producing steel, was named after Bessemer.

Harold Urey (1893-1981) :

Harold Urey was an American physical chemist, who won the 1934 Noble prize in chemistry for his work on isotopes, specifically the discovery of deuterium, a hydrogen isotope, and the production of heavy water. He also performed pioneering research in cosmochemistry, which studies the origin and development of elements and their isotopes, primarily within the solar system. Urey, along with his student Stanley Miller, may be best remembered for the renowned Miller-Urey experiment, which shows that a mixture of ammonia, methane and hydrogen, when exposed to ultraviolet radiation and water, can interact to form amino acids, the "building blocks" of terrestrial life. This experiment followed on from Urey's work on the oxygen isotope 18O, and is considered to be pioneering work in the field of paleoclimatology, as it attempts to explain the composition of the early Earth's atmosphere.

Hermann Emil Fischer (1852-1919) :

Hermann Emil Fischer was a German chemist and recipient of the Noble prize for chemistry in 1902. Many consider Fischer to be the most brilliant chemist who ever lived, because of his numerous contributions to science, especially chemistry and biochemistry. Among these is his discovery of phenylhydrazine. He also undertook vast studies on purines. This work showed that various substances such as adenine, xanthene, caffeine, uric acid, and guanine, all belonged to one homogeneous family, and could be derived from one another. He reasoned this to be due to their common origins from a parent molecule, a bicylic nitrogenous structure into which the characteristic urea group entered. Fischer regarded this structure as hypothetical, and named it 'purine' in 1884. He synthesized it in 1898. He is also famed for his work on sugars.

Irene Joliot-Curie (1897-1956) :

French physicist was born in Paris in September 12th 1897, daughter of Pierre and Marie Curie, died in Paris, in March 17th 1956. She along with her husband, Jean Frederic Joliot won the Nobel Prize for Chemistry in 1935 for their works in the artificial induction of radioactivity.

Irving Langmuir (1881-1957) :

North-American scientist was born in Brooklyn, New York, in January 31st 1881, and died in Massachusetts in August 16th 1957. He had a special interest in surface chemistry, being responsible for the explanation of surface action that granted him the Nobel Prize of Chemistry in 1932. Invented electric lamps in gaseous atmospheres, measured the melting point of refractory solids and discovered atomic HYDROGEN. As a result of his research on gaseous reaction kinetics derived the adsorption isothermic named after him. Langmuir also studied the hypothesis of producing artificial rain (1946

Jacques A. Cesar Charles (1746-1823) :

French Physicist, born in Beaugency (1746) and died in Paris (1823). In 1783 performed the first flight in a hydrogen balloon (the previous flights were accomplished with hot air). His studies on gas expansion led to the discovery of the law that rules the volume variation of a perfect gas with temperature (1787). The first enunciation of this law was published later (1802) by Gay-Lussac therefore and it is often referred as the Charles and Gay Lussac Law. Charles also determined the water density at different temperatures.

Jacobus Henricus van’t Hoff (1852-1911) :

Jacobus Henricus van’t Hoff was a Dutch physical and organic chemist, and recipient of the inaugural Noble Prize for chemistry. He accounted for the phenomenon of optical activity by assuming that the chemical bonds between carbon atoms and their neighbors were directed towards the corners of a regular tetrahedron. This three-dimensional structure perfectly accounted for the isomers found in nature (stereochemistry). He shares credit for this idea with the French chemist Joseph Le Bel, who independently came up with the same idea. He received the first Nobel Prize for his work on relating the behaviour of solutions to that displayed by gases.

James Prescott Joule ( 1818- 1889) :

James Prescott Joule was an English physicist and brewer, born in Salford, Lancashire. Joule studied the nature of heat, and discovered its relationship to mechanical work (see energy). This led to the theory of conservation of energy, which led to the development of the first law of thermodynamics. The SI derived unit of energy, the joule, is named after him. He worked with Lord Kelvin to develop the absolute scale of temperature, made observations on magnetostriction, and found the relationship between the current through a resistance and the heat dissipated, now called Joule's law.

Julius Robert von Mayer (1814-1878) :

Julius Robert von Mayer was a German physician and physicist and one of the founders of thermodynamics. He is best known for enunciating in 1841 one of the original statements of the conservation of energy or what is now known as one of the first versions of the first law of thermodynamics, namely: “ Energy can be neither created nor destroyed ” In 1842, Mayer described the vital chemical process now referred to as oxidation as the primary source of energy for any living creature. His achievements were overlooked and priority for the discovery of the mechanical equivalent of heat was attributed to James Joule in the following year. He also proposed that plants convert light into chemical energy.

Jean Frederic Joliot-Curie (1900-1958) :

French physicist, whose bachelor’s name was Jean Frederic Joliot, was born in Paris in March 19th 1900 and died in Paris, in August 14th 1958. He with his wife Irene Curie won the Nobel Prize of Chemistry in 1935, for the artificial production of radioactive substances. In 1940, along with Irene, collaborated in the chain reactions studies of nuclear fission. In 1948, announced the discovery of a new particle in the atomic nucleus called “lambda mesatron”. In 1951, received the Stalin’s Peace Prize, awarded by the Soviet Union.

John Dalton (1766-1844) :

English scientist and teacher, born in Eaglesfield, in September 6th 1766, and died in Manchester, in July 27th 1844, is the founder of atomic theory. In 1794 studied the phenomena that later became known as daltonism. After that he started to study Chemistry, the physical behavior of gases and in 1803 proposed the principles of atomic theory to explain the constitution of matter. Dalton is therefore the man responsible for the scientific approach to the old theories of Democritus.

Jons Jakob Berzelius (1779-1848) :

Berzelius was a Swedish chemist and a teacher born, in Linkoping, in August 29th 1779, and died in Stockholm, in August 7th 1848. He is considered one the founders of modern Chemistry. In 1822, entered the French Institute and was responsible for the mineral classification according to its chemical composition. His studies in electrolysis led him to the basis of electrochemical theories. Determined the atomic weight of 43 elements. He isolated calcium, barium, strontium, silicon, titanium, zirconium and discovered selenium, thorium and cesium. He recognized the existence of isomers (in Organic Chemistry) and discovered the catalysis phenomenon.

Joseph-Louis Gay-Lussac (1778-1850) :

French physicist, chemist and professor, Gay-Lussac was born in Saint Leonard de Noblat, Marche, in December 6th 1778 and died in Paris, in May 9th 1850. Along with Louis-Jacques Thénard, followed the work of Davy being responsible for the discovery of boron and iodine. In 1804, working at the Institute of France, performed two balloon ascensions with the purpose of studying the chemistry and physics of the outer layers of the atmosphere. His most important research refers to the gas expansion, with special relevance to the well known Gay-Lussac law.

Sir James Dewar (1842-1923) :

Scottish chemist, physicist and professor was born in Kincardine-on-Forth, in September 20th 1842 and died in London, in March 27th 1923. He developed a chemical formula for benzene and performed extensive work in spectroscopy for more than 25 years. In 1891 discovered a process to produce liquid oxygen in industrial quantities. He also developed an insulating bottle, still named after him nowadays, to study low temperature gas phenomena. He also used this bottle to transport liquid gases like HYDROGEN (1898). In 1905 observed that cold charcoal could produce vacuum. This technique was quite useful for the experiments in atomic physics. Along with Sir Frederick Augustus Abel, he developed the explosive whose common name is CORDITE.

Sir Joseph Norman Lockyer (1836-1920) :

English astronomer and professor, was born in Rugby in May 17th 1836 and died in Sidmouth in August 16th 1920. He was interested in solar spectroscopy discovered, together with P.J.Janssen, the prominences (red flames) that surround the solar disk. Lockyer discovered the element HELIUM in the Sun before it had been detected on Earth. He was also interested in the classification of stellar spectra and developed the meteoric hypotheses of stellar evolution.

John Alexender Reina Newlands(1837-1898) :

John Alexander Reina Newlands (November, 1837 – July 29 1898) was an English analytical chemist who prepared in 1863 the first periodical table of the elements arranged in order of relative atomic weight, and pointed out in 1865 the 'law of octaves' whereby every eighth element has similar properties. The incompleteness of a table he drew up 1864 he attributed to the possible existence of additional, undiscovered elements. For example, he predicted the existence of germanium. Newlands was born in London and studied there at the Royal College of Chemistry.

Johann Wolfgang Döbereiner(1780-1849) :

Around 1817, Döbereiner noticed a pattern among three elements with similar chemical properties, chlorine, bromine, and iodine. Specifically, he noted that the atomic weight of bromine (80.970) was the arithmetic mean of the atomic weights of chlorine (35.470) and iodine (126.470). The currently accepted atomic weight for bromine was 80.470. Furthermore, the properties of the three elements varied in an orderly manner, from chlorine to bromine to iodine. Döbereiner spoke of this group of elements as a triad. He found two other triads among the known elements. One triad consisted of calcium, strontium, and barium; the other of sulfur, selenium, and tellurium. Other chemists attempted to find other triads among the elements, but, overall, Döbereiner's discovery seemed to be a dead end. Thus, chemists largely ignored the Law of Triads. Not until Dmitri Mendeleev's discovery of the periodic law four decades later did the significance of Döbereiner's discovery finally become apparent. Döbereiner died at Jena on March 24, 1849, 20 years before Mendeleev published his periodic law

Julius Lothar Meyer(1830-1895) :

Meyer is best known for the share he had in the periodic classification of the elements. He noted, as did J.A.RNewlands in England, that if they are arranged in the order of their atomic weights they fall into groups in which similar chemical and physical properties are repeated at periodic intervals; and in particular he showed that if the atomic weights are plotted as ordinates and the atomic volumes as abscissae, the curve obtained presents a series of maxima and minima, the most electro-positive elements appearing at the peaks of the curve in the order of their atomic weights. In 1882, Meyer received from the Royal Society, the Davy Medal in recognition of his work on the Periodic Law. Meyer's contributions also included the concept that the carbon atoms in benzene were arranged in a ring, although he did not propose the alternation of single and double bonds that later became included in the structure by Kekule..

J.J. Thomson(1856-1940) :

Joseph John Thomson was born in Cheetham Hill, a suburb of Manchester on December 18, 1856 On April 30, 1897, Thomson announced that cathode rays were negatively charged particles which he called 'corpuscles.' He also announced that they had a mass about 1000 times smaller than a hydrogen atom, and he claimed that these corpuscles were the things from which atoms were built up. Later in 1897, he wrote: "...we have in the cathode rays matter in a new state, a state in which the subdivision of matter is carried very much farther than in the ordinary gaseous state: a state in which all matter-that is, matter derived from different sources such as hydrogen, oxygen, etc.-is of one and the same kind; this matter being the substance from which the chemical elements are built up." Thomson was the first to say that the cathode ray was a building block of the atom. It was a risky thing, but he was proved right and for his courage he is remembered as the discoverer of the electron.

Johann Wolfgang Döbereiner (1780 – 1849) :

Johann Wolfgang Döbereiner was a German chemist who is best known for work that foreshadowed the periodic law for the chemical elements. Döbereiner also is known for his discovery of furfural, for his work on the use of platinum as a catalyst, and for a lighter, known as Döbereiner's lamp.

Kekule von Stradonitz, Friedrich (1829-1896) :

German chemist, who introduced the concept of the chemical bonds, the tetravalent carbon atom, and the use of structural formulas to explain the formation of molecules. He proposed a structure for benzene consisting of a ring of carbon atoms with alternating double and single bonds. Kekulé was the first to define organic chemistry as the chemistry of carbon compounds. He thought the application of atomism was useful to explain the chemical properties of compounds, but also believed in the actual existence of atoms. His use of chemical structures was extended by van't Hoff and Le Bel.

Louis de Broglie(1892–1987) :

He was born at Dieppe (Seine Inférieure) on 15th August, 1892,in a noble French family. In his doctoral dissertation in 1924, Louis de Broglie developed the equation ? = h/m?, which predicts that the wavelength ? of a particle is inversely proportional to its mass m and velocity ? where h is Planck's constant.? The wavelength associated with a submicroscopic object—an electron, for example—is large relative to the size of the object and is therefore significant in describing its behavior, whereas the wavelength associated with a macroscopic object—a basketball, for example—is negligibly small relative to its size, and therefore the wavelike behavior of such an object is unnoticeable. The dual nature of electrons proposed by de Broglie, together with the dual nature of electromagnetic radiation proposed by Max Planck, led to the development of quantum mechanics by the Austrian physicist Erwin Schrödinger in 1926. He received the Nobel Prize in physics in 1929.

Le Bel, Achille (1847-1930): :

Joseph Achille Le Bel , 1847-1930, French chemist. He was educated at the École polytechnique and carried out much of his research in his own private laboratory. He theorized (1874) that optical activity—the presence of two forms of the same organic molecule, one a mirror image of the other—is due to an asymmetric carbon atom bound to four different groups. For this contribution he is regarded as the cofounder of stereochemistry, with J. H. van't Hoff. His interests also included petrochemistry, cosmology, and biology He independently of van’T Hoff, proposed a theory relating optical activity to molecular structure. He was able to determine the molecular geometry by the number of stereoisomers possible.

Marie Curie (1867-1934) :

Polish scientist was born in Warsaw, in November 7th 1867, and died in France, in 4th July 1934. Her single name was Maria Sklodowska. In 1896, H Becquerel suggested the theme of her Ph.D. thesis the study of natural radiation from uranium salts. Curie and her French husband, Pierre Curie discovered and isolated a new radioactive element named polonium in honor to Marie's home land. A few months later, they were able to isolate radium for the first time. Together with Becquerel, she obtained the Noble Prize for Physics in 1903. In 1911 she was awarded the Noble Prize for chemistry.

Max Planck (April 23, 1858 – October 4, 1947) :

He was a German physicist. He is considered to be the founder of the quantum theory, and one of the most important physicists of the twentieth century. Planck was awarded the Nobel Prize in Physics in 1918.

Michael Faraday (1791-1867) :

English chemist and physicist was born in Surrey, in September 22nd 1791 and died in Hampton Court, in August 25th 1867. In 1831 discovered the electromagnetic induction and in 1833 studied the problems if electrolysis performing basilar discoveries and introducing the concepts of electrolysis, cathode, anode, ion, etc. Later on he studied the electrostatic induction, being responsible for the construction of the first Faraday cage. Finally, he discovered in 1845 the rotating magnetic polarization, of enormous importance to modern magnetism. Faraday described certain elements and chemical compounds such as chlorine and benzene

Niels Bohr (1885-1962) :

Danish physicist, Bohr was born in Copenhagen, in 1885, and died also in this city in 1962. Bohr graduated in his birth city, in 1911, and worked with J.J Thomson and E.Rutherford in England. In 1913, by applying the atomic model of Rutherford was able to understand some of the spectral series of hydrogen and the structure of the periodic system of elements. He announced the correspondence principle and, in 1928, the complementary principle. Bohr studied the liquid drop nuclear model, and before the discovery of plutonium, foresighted its fission property, similar to that of U-235. Bohr received the Nobel Prize of Physics in 1922.

Otto Hahn (1879-1968) :

A German chemist was born in March 8th 1879, in Frankfurt-am-Main and died in July 28th 1968 in Goettingen. In 1905, working with Sir William Ramsay in London discovered the radioisotope thorium. In 1907, working with Rutherford in Canada discovered the radio-actinium. He discovered meso-thorium, used instead of radium in medical applications. Hahn and his co-workers discovered protactinium. In 1935, together with Meitner and Strassman, Hahn begun to work in Uranium bombardment with neutrons, which led to the discovery, in 1938, of nuclear fission. For this work he was awarded the Nobel Prize of Chemistry in 1944.

Ostwald, Friedrich Wilhelm (1853-1932) :

In 1881 Ostwald became professor at a polytechnic institute in Riga, in 1887 in Leipzig (first chair for physical chemistry). After 1877 Ostwald occupied himself with the problem of chemical affinities and of slow chemical reactions. After 1884 together with Svante Arrhenius he studied the conductivities of electrolytes and found the ´law of dilution´ (Verdünnungs-gesetz). He also worked on the equilibria and velocities of chemicals and established a ´rule of steps´ (Stufenregel) for the gradual course of certain chemical reactions. Other fields of investigation were catalysis (preparation of nitric acid, autocatalysis) and systematisation of colours. Ostwald also wrote extensively on natural philosophy and the history of science. In 1909 he was awarded the Nobel prize for chemistry.

Peter Joseph Wilhelm Debye (1884-1966) :

Dutch physicist and professor was born in Maastricht, in 1884 and died in the same city in 1966. He established a theory of specific heat with some improvements on that proposed by Einstein. He carried out important work in the analysis of crystalline powders using X-ray diffraction techniques. He determined the dimensions of gaseous molecules and the interatomic distances using X-rays. This work granted him the Nobel Prize of Chemistry in 1936.

Planck, Max (1858-1947): :

Max Planck, born in Kiel, Germany, & at the tender age of 16, entered the University of Munich; there he studied physics. At the age of 21 years, Planck received a doctorate; his thesis being on the second law of thermodynamics. He then went on to teach, first at the University of Munich (1880), then University of Berlin (1889) where he stayed for 38 years until he retired in 1927. It was in 1900 that Planck set out a formula now known as Planck's radiation formula, which formula, effectively renounced classical physics and introduced the quanta of energy. At first the theory met resistance, but, due to the successful work of Neil’s Bohr, the theory was to become generally accepted. Planck received the Nobel Prize for Physics in 1918

Priestley, Joseph (1733-1804): :

Priestley was an English presbyterian minister and chemist. He was, one of the discoverers of oxygen." He assisted Benjamin Franklin in the writing of, The History of Electricity in 1767 In 1772 he was appointed to the French Academy of Sciences; and, in 1780, the St. Petersburg Academy.

Proust, Joseph-Louis (1754-1826) :

French chemist who maintained the proportions of substances which combined in a reaction were always the same, known as the Law of Definite Proportions or Proust's Law. This opposed the ideas of Berthelot who thought that the course of a reaction depended on the original mass of reactants.

Robert Boyle (1627-1691) :

Boyle, a chemist and physicist, was born in Lismore Castle, Munster, Ireland, in January 25th 1627, and died, in London, in December 30th 1691. Boyle is sometimes considered the "father of modern Chemistry". He was one of the first researchers to have a scientific approach to the atomism of the Ancient Greeks, as an opposition to the four element theory of Aristotle and the Paracelsus theories. His book The Sceptical Chemist opened a new era in the history of Chemistry, where terms like atom or molecule appeared. Boyle is often considered the founder of chemical analysis due to his studies of materials composition. His skeptical attitude was not enough to avoid some passionate work in alchemy. He invented a vacuum pump and used it in the discovery of what has become known as Boyle's law. Boyle also made important work in hydrostatics, sound and breathing phenomena, being responsible, along with Hooke, for the construction of the pneumatic machine performing various gas pressure experiences. He also verified the inverse relationship between pressure and volume at constant temperature (Law of Boyle-Mariotte).

Robert Wilhelm Eberhard von Bunsen (1811-1899) :

Bunsen, a German, was scientist and Professor and was born in Gottingen, in March 31st 1811, and died in Heidelberg, in August 16th 1899. Bunsen performed a series of researches with rubidium and cesium through the spectroscopic analysis. His name is associated to several Physics instruments like the Bunsen-burner (used in laboratory for heating through gas combustion), Bunsen-effuser (determines gas density by velocity measurement of gas drain through a small hole) and grease-spot photometer (used to compare intensity of similar light sources).

Richter, Jeremias Benjamin (1762-1807) :

Richter studied philosophy, under Immanuel Kant, and mathematics at Königsberg. In1785 he obtained a doctoral degree with a dissertation on the use of mathematics in chemistry. He never reached an academic position and experimented at his own expense. His most important contribution to chemistry was the discovery of the law of equivalent proportions. He also introduced the term 'stoichiometry' into

Rutherford, Ernest (1871-1937). :

Ernest Rutherford was born on August 30, 1871, in Nelson, New Zealand. He invented a detector for electromagnetic waves, an essential feature being an ingenious magnetizing coil containing tiny bundles of magnetized iron wire. He worked jointly with Thomson on the behaviour of the ions observed in gases which had been treated with X-rays, and also, in 1897, on the mobility of ions in relation to the strength of the electric field, and on related topics such as the photoelectric effect. In 1898 he reported the existence of alpha and beta rays in uranium radiation and indicated some of their properties. Rutherford was the greatest of the pioneers of subatomic physics. He led us to the confines of knowledge in respect of the ultimate structure and constitution of matter.

Ramsay, William (1852-1916) :

Ramsay studied chemistry at the University of Glasgow (1866) and in Germany under Bunsen (1871). He obtained his Ph.D. at the University of Tübingen and became professor of chemistry at the University College in Bristol (1880) and at the University College in London (1887). Although chiefly interested in organic chemistry he grew intrigued by the problem posed by Rayleigh (1892) that nitrogen obtained from air was denser than that obtained from compounds. Using the spectroscope Ramsay and Rayleigh could identify a new family of chemical elements with valence of zero. They discovered the noble gases: argon (1894), helium (1895), and neon, krypton and xenon (1898). Ramsay received the Nobel Prize in chemistry in 1904, while Rayleigh received the Nobel Prize in physics the same year.

Scheele, Carl Wilhelm (1742-1786) :

At the age of fourteen Scheele was apprenticed to an apothecary in Gothenburg and later in Malmö where he started to conduct chemical experiments. While working in a pharmacy in Uppsala in 1770 he was introduced to the leading Swedish chemist of that time T.O. Bergman. Scheele received advice and help from Bergman but never formally studied chemistry. Nevertheless, he became one of the greatest experimental chemists of all times discovering new elements and substances in greater variety than any other person before him. He was involved in the discovery of the elements and simple compounds of chlorine, fluorine, manganese, barium, molybdenum, tungsten and oxygen. It has been established that Scheele's discovery of oxygen took place in 1771, or before Priestley and Lavoisier. Scheele published his studies mostly in the proceedings of the Royal Academy of Sciences in Stockholm which called the self-made scientist to be its full member. Due to the significant achievements in inorganic chemistry, Scheele's accomplishments in organic chemistry are often overlooked. He was the first one to separate and characterise organic acids such as tartaric, citric, benzoic, malic and oxalic. Since 1775 Scheele worked as an apothecary in a small town of Köping where he also died at the early age of 43 years. His death may have been caused by long-term exposure to highly toxic substances such as arsenic acid and hydrogen cyanide which also belong to the compounds first prepared by Scheele.

Solvay, Ernest (1838-1922) :

Solvay had little formal education. In the gasworks of his uncle he worked out several methods of purifying gas. He dissolved ammonia and carbon dioxide in salt water, the solution produced a precipitate that turned out to be sodium bicarbonate. Solvay took out his first patent in 1861, founded a company and after three years settled down to success. By 1913 he was producing virtually the entire world supply of sodium bicarbonate. He founded the International Institute for Physics and Chemistry in Brussels (1894), where the famous Solvay-congresses were held.

Soddy, Frederick (1877-1956) :

Soddy studied chemistry in Oxford and graduated in 1898. He worked under Rutherford. Soddy studied the different consecutive radioactive breakdowns beginning with uranium and thorium. In the process of disintegration some fourty to fifty different elements were detected. Soddy suggested that different elements were capable of occupying the same place in the periodic table. In 1913 he called these elements isotopes. Furthermore he could explain all radioactive intermediates and that lead was the final stable element. For these results Soddy was awarded the Nobel Prize for chemistry in 1921. He was professor of chemistry in Oxford from 1919-1936

Sörensen, Soren Peter Lauritz (1868-1939) :

Sørensen first began to study medicine at the University of Copenhagen but soon moved to chemistry where he obtained his Ph.D. in 1899 working under S.M. Jørgensen on inorganic syntheses. Sørensen became director of the chemical section of Carlsberg Laboratories in 1901 and retired from this post in 1938. While at the Carlsberg Laboratories, Sørensen started to study amino acids, proteins and enzymes. Because hydrogen ion concentration played a key role in enzymatic reactions he devised a simple way of expressing it. By taking a negative logarithm of hydrogen ion concentration a convenient scale can be established; this is the well-known pH value. He also developed buffer solutions to maintain constant pH of solutions (Sørensen buffers).

Torricelli, Evangelista (1608-47): :

Torricelli, Italian scientist, was a helper to Galileo. He is known for the invention of the "Torricellian tube." It was on account of Torricelli's experiments that we were to come to better understanding nature of atmospheric pressure, for example, it was Torricelli who first determined that water will not rise above 33 feet in a suction pump. . His efforts also led to considerable improvements to both the telescope and microscope.

Volta, Alessandro, Count (1745-1827): :

Volta was the Italian physicist which will always be remembered by the label "volt," one applied to describe a unit of electric pressure. It was Volta who developed the theory of current electricity; further, that water might be decomposed through the application of electricity; and further, he invented the electric battery.

Wöhler, Friesrich (1800-82): :

Wöhler, born near Frankfurt and educated at Heidelberg, was to become a professor at Göttingten in 1836. Wöhler's work led to him isolating aluminium. "His synthesis of urea from ammonium cyanate in 1828 revolutionized organic chemistry."

Werner Heisenberg (1901-1976) :

Heisenberg was born in Duisverg, Germany in December 15th 1901 and died in Munich, in February 1st 1976. He proposed a mathematical treatment of the atomic behaviour. In 1925, with the help of Born and Jordan, developed this idea giving birth to a theory compatible with quantum mechanics. In 1927, he discovered the uncertainty principle and explained ferromagnetism based on the atomic structure. He was awarded the Nobel Prize of Physics in 1932.

Wolfgang Pauli(1900-1958) :

Wolfgang Pauli was born on April 25th, 1900 in Vienna. He received his early education in Vienna before studying at the University of Munich under Arnold Sommerfeld. He obtained his doctor's degree in 1921 and spent a year at the University of Göttingen as assistant to Max Born and a further year with Neils Bohr at Copenhagen. His exclusion principle, which is often quoted bearing his name, crystallized the existing knowledge of atomic structure at the time it was postulated and it led to the recognition of the two-valued variable required to characterize the state of an electron. Pauli was the first to recognize the existence of the neutrino, an uncharged and massless particle which carries off energy in radioactive ß-disintegration II. He received Noble prize in 1945

Werner, Alfred (1866-1919) :

Werner earned his Ph.D. at the University of Zürich in Switzerland (1890) and did postdoctoral work with Berthelot in Paris. Beginning 1891 he developed a co-ordination theory of molecular structure. Co-ordination bonds were often spoken of as secondary valence. In 1913 he was awarded the Nobel Prize for chemistry.

Wurtz, Charles Adolphe (1817-1884) :

Wurtz embarked on medical studies, but studied chemistry under Liebig (Giessen). In Paris he gained professorial status (1853). He was the first professor of organic chemistry at the Sorbonne (1875). Wurtz was the first important chemist in France to support the structural views of Laurent. In 1855 he discovered the still called "Wurtz-reaction". He prepared many different substances.

 

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