Gilbert Newton Lewis (October 25 (or 23), 1875 - March 23, 1946) is an American physical physicist known for his discovery of the covalent bond and the concept of his electron pair; Lewis's point structure and other contributions to valence bond theory have formed the modern theory of chemical bonding. Lewis manages to contribute to thermodynamics, photochemistry, and isotope separation, and is also known for the concept of acids and bases.
G. N. Lewis was born in 1875 in Weymouth, Massachusetts. After receiving a PhD in chemistry from Harvard University and studying abroad in Germany and the Philippines, Lewis moved to California to teach chemistry at the University of California, Berkeley. A few years later, he became Dean of the Faculty of Chemistry at Berkeley, where he spent the rest of his life. As a professor, he incorporated thermodynamic principles into the chemical curriculum and reformed chemical thermodynamics in a rigorous mathematical fashion accessible to ordinary chemists. He began measuring the value of free energy associated with several chemical processes, both organic and inorganic.
In 1916, he also proposed his theory of ties and added information about electrons in the periodic table of chemical elements. In 1933, he began his research on isotope separation. Lewis worked with hydrogen and succeeded in purifying heavy water samples. He then came up with acidic and alkaline theories, and worked in the field of photochemistry during the last years of his life. In 1926, Lewis coined the term "photon" for the smallest luminous energy unit. He is a brother in Alpha Chi Sigma, a professional chemical brotherhood.
Although he was nominated 41 times, G. N. Lewis never won a Nobel Prize in Chemistry. On March 23, 1946, Lewis was found dead in the Berkeley laboratory where he worked with hydrogen cyanide; many suspect that the cause of his death was suicide. After Lewis's death, his children followed their father's career in chemistry.
Video Gilbert N. Lewis
Biography
Initial life
Lewis was born in 1875 and raised in Weymouth, Massachusetts, where there is a street named for him, G.N. Lewis Way, from Summer Street. In addition, the wing of the department of High School of Weymouth High School has been named in his honor. Lewis received basic education at home from his parents, Frank Wesley Lewis, an independent character lawyer, and Mary Burr White Lewis. He read at the age of three and was intellectually mature prematurely. In 1884 his family moved to Lincoln, Nebraska, and in 1889 he received his first formal education at a university prep school.
In 1893, after two years at the University of Nebraska, Lewis moved to Harvard University, where he earned a B.S. in 1896. After a year teaching at the Phillips Academy in Andover, Lewis returned to Harvard to study with the physical chemist T. W. Richards and obtained his Ph.D. in 1899 with a dissertation on electrochemical potential. After a year teaching at Harvard, Lewis took a scholarship trip to Germany, a physical chemistry center, and studied with Walther Nernst in GÃÆ'¶ttingen and with Wilhelm Ostwald in Leipzig. While working in the Nernst lab, Nernst and Lewis apparently developed a lifelong animosity. In the following years, Lewis began to criticize and criticize his former teacher on many occasions, calling Nernst's work on his hot theorem "a regret episode in chemical history". A friend of Nernst, Wilhelm PalmÃÆ'Â|r (Sweden), is a member of the Nobel Committee of Chemistry. There is evidence that he used the Nobel nomination and reporting procedure to block the Nobel Prize for Lewis in thermodynamics by nominating Lewis for a three-time prize, and then using his position as a committee member to write a negative report. Harvard, Manila, and MIT
After living in the Nernst lab, Lewis returned to Harvard in 1901 as an instructor for three more years. He was appointed as an instructor in thermodynamics and electrochemistry. In 1904 Lewis was granted leave of absence and became a Load and Measurer for the Bureau of Science in Manila, Philippines. The following year he returned to Cambridge, Massachusetts when the Massachusetts Institute of Technology (MIT) raised him to a faculty position, where he had the opportunity to join a group of outstanding physical chemists under Arthur Amos Noyes's direction. He became an assistant professor in 1907, professor in 1908, and a full professor in 1911. He left MIT in 1912 to become a professor of physical chemistry and dean of the College of Chemistry at the University of California, Berkeley. Lewis Hall in Berkeley, built in 1948, is named in his honor.
Thermodynamics
Most of Lewis' lasting interest originated during his Harvard years. The most important is thermodynamics, the subject where Richards was very active at the time. Although most important thermodynamic relations are known by 1895, they are seen as isolated equations, and have not been rationalized as logical systems, from which, given a relation, the rest can be derived. In addition, this relationship is not appropriate, only applicable to ideal chemical systems. These are two remarkable theoretical thermodynamic problems. In two lengthy and ambitious theoretical papers in 1900 and 1901, Lewis tried to provide a solution. Lewis introduced the concept of thermodynamic activity and coined the term "fugasitas". His new idea of ​​fugasitas, or "escape tendency", is a function with a pressure dimension that states the tendency of a substance to move from one chemical phase to another. Lewis believes that fugasitas is the fundamental principle from which a real thermodynamic relation system can be derived. This hope does not materialize, though famanitas finds a lasting place in a real gas description.
Lewis's early letters also revealed a remarkable awareness of the ideas of J. W. Gibbs and P. Duhem about free energy and thermodynamic potential. These ideas are well known to physicists and mathematicians, but not to most practical chemists, who regard them as elusive and do not apply to chemical systems. Most chemists rely on thermodynamics of heat (enthalpy) from Berthelot, Ostwald, and Van't Hoff, and calorimetric schools. The heat of the reaction is not, of course, a measure of the trend of chemical change taking place, and Lewis realizes that only free energy and entropy can provide precise chemical thermodynamics. It obtains free energy from evil; he tried, unsuccessfully, to obtain the proper expression for entropy function, which in 1901 had not been defined at low temperatures. Richards tried too much and failed, and it was not until Nernst succeeded in 1907 that it was possible to compute entropy clearly. Although Lewis's obesity-based system did not last long, his early interest in free energy and entropy proved most useful, and much of his career was devoted to making these useful concepts accessible to practical chemists.
At Harvard, Lewis also wrote a theoretical paper on the thermodynamics of black body radiation in which he postulates that light has pressure. He then reveals that he has been discouraged from pursuing this idea by his older, more conservative colleagues, unaware that Wilhelm Wien and others have pursued the same line of thought. Lewis paper remains unpublished; but his interest in radiation and quantum theory, and (later) in relativity, emerged from this beginning, a failed attempt. From the beginning of his career, Lewis considered himself a chemist and physicist.
Valence Theory
Around 1902 Lewis began using unpublished images of cubic atoms in his lecture notes, where the angle of the cube represented possible electron positions. Lewis then cites this note in his classic paper on chemical bonds, as the first expression of his ideas.
The third major interest that came during Lewis' Harvard year was his valence theory. In 1902, while attempting to explain the law of valence to his disciples, Lewis conceived the idea that atoms were constructed from a series of concentric cubes with electrons in every corner. This "cubic atom" explains the eight-element cycle in the periodic table and corresponds to the widely accepted belief that chemical bonds are formed by the transfer of electrons to give each atom a complete set of eight. This theory of electrochemical valence finds the most complicated expression in Richard Abegg's work in 1904, but Lewis's theory of this version is the only one to be embodied in a concrete atom model. Again, Lewis's theory did not attract his Harvard mentors, who, like most American chemists at the time, had no such speculative appetite. Lewis did not publish his theory of cubic atoms, but in 1916 it became an important part of his theory of the bonding of electron pairs together.
In 1916 he published his classic paper on the chemical bonds of "Atoms and Molecules" in which he formulated the notion of what would be known as a covalent bond, consisting of a pair of electrons together, and he defined the strange molecular term (the modern term is free radical) when an electron is not shared. He includes what is known as the Lewis dot structure as well as the cubic model of the atom. These ideas on chemical bonding were expanded by Irving Langmuir and became the inspiration for the study of the nature of chemical bonds by Linus Pauling.
Relativity
In 1908 he published the first of several papers on relativity, where he gained mass-energy relationships in a way different from Albert Einstein's derivation. In 1909, he and Richard C. Tolman combined his methods with special relativity. In 1912 Lewis and Edwin Bidwell Wilson presented the major work in mathematical physics that applied not only synthetic geometry to the study of spacetime, but also noted the identities of spacetime extortion mapping and Lorentz transformations.
In 1913, he was elected to the National Academy of Sciences. He resigned in 1934, refusing to state the reasons for his resignation; have speculated that it was because of a dispute over the organization's internal politics or their nominated failure to be elected. His decision to resign may have been fueled by a hatred of the 1934 Nobel Prize for chemistry to his student Harold Urey for the discovery of deuterium, a reward that Lewis almost certainly feels he should share for his work on purification and characterization. heavy water.
Acids and bases
In 1923, he formulated the electron-pair theory of acid-base reactions. In the theory of acids and bases, "Lewis Acid" is the electron-pair acceptor and "Lewis base" is the electron-pair donor . This year he also published a monograph on his theory of chemical bonds
Based on work by J. Willard Gibbs, it is known that the chemical reaction proceeds to a balance determined by the free energy of the partaking agent. Lewis spent 25 years to determine the free energy of various substances. In 1923 he and Merle Randall published the results of this study, which helped formulate the thermodynamics of modern chemistry.
Water
Lewis was the first to produce a pure sample of deuterium oxide (heavy water) in 1933 and the first to study the survival and growth of life forms in heavy water. By accelerating the deuteron in the Ernest O. Lawrence cyclotron, he is able to study many of the properties of atomic nuclei. During the 1930s, he was a mentor to Glenn T. Seaborg, who maintained for post-doctoral work as Lewis's personal research assistant. Seaborg later won the 1951 Nobel Prize in Chemistry and has a seaborgium element named in his honor when he was alive.
Other achievements
In 1921, Lewis was the first to propose an empirical equation depicting a strong electrolyte failure to obey the law of mass action, a problem that has puzzled the physical chemist for twenty years. The empirical equation for what he calls ionic strength is then confirmed to correspond to the Debye-HÃÆ'¼ckel equation for the powerful electrolyte, published in 1923.
In 1924, by studying the magnetic properties of the oxygen solution in liquid nitrogen, he discovered that the molecules of O 4 were formed. This is the first evidence for tetratomic oxygen.
In 1926, he coined the term "photon" for the smallest unit of radiation energy (light). Actually, the result of his letter to Nature is not what he meant. In the letter, he proposes photons to be structural elements, not energy. He emphasized the need for new variables, the number of photons . Although his theory differs from the quantum theory of light introduced by Albert Einstein in 1905, his name was adopted for what Einstein called a bttquant in German.
Next year
During his career, Lewis publishes many other subjects other than those mentioned in this entry, ranging from the nature of light quanta to the economy of price stabilization. In the later years of his life, Lewis and graduate student Michael Kasha, his latest research colleagues, determined that organic molecular salting involves light emitting from one electron in an excited triplet state (a state in which two electrons have a spin oriented vector in the direction of but in different orbital) and measure the paramagnetism of the status of this triplet.
In 1946, a graduate student found Lewis's lifeless body beneath the laboratory desk at Berkeley. Lewis has worked on experiments with liquid hydrogen cyanide, and the deadly smoke from dashed lines has leaked into the laboratory. The coroner ruled that the cause of death was a coronary artery disease, due to a lack of signs of cyanosis, but some believed it might be suicide. Berkeley Professor Emeritus William Jolly, who reported various views on Lewis's death in his 1987 history from the UC Berkeley College of Chemistry, wrote from a retorts to Lasers writing that a department official believed that Lewis had committed suicide.
If Lewis's death was suicidal, the possible explanation was the depression brought by lunch with Irving Langmuir. Langmuir and Lewis had long rivalries, derived from Langmuir's extension of Lewis's theory of chemical bonds. Langmuir has been awarded the 1932 Nobel Prize in chemistry for his work on surface chemistry, while Lewis has not received the Prize despite having been nominated 41 times. On the day Lewis died, Langmuir and Lewis met for lunch at Berkeley, a meeting that Michael Kasha remembered only a few years later. Associates reports that Lewis returned from lunch in a dark atmosphere, playing a grim game of bridges with some colleagues, then back to work in the lab. An hour later, he was found dead. Langmuir's papers at the Library of Congress confirmed that he was on the Berkeley campus that day to receive an honors degree.
Maps Gilbert N. Lewis
Personal life
On June 21, 1912, he married Mary Hinckley Sheldon, daughter of a professor of Romance at Harvard. They have two sons, both become professors of chemistry, and a daughter.
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See also
- History of molecular theory
References
Further reading
- Coffey, Patrick (2008) Cathedral of Science: Personality and Competition Who Makes Modern Chemistry . Oxford University Press. ISBN 978-0-19-532134-0
External links
- Main Participants: G. N. Lewis - Linus Pauling and Nature of the Chemical Association: Documentary History
- Eric Scerri, The Periodic Table, The Story and Its Important Meaning, Oxford University Press, 2007, see chapter 8 in particular
- National Academy of Biographical Sciences Memo
Source of the article : Wikipedia
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