October 23 is Gilbert Newton Lewis’ birthday. Lewis was an American chemist best known for his valence bond theory and electron dot structures.
Lewis spent much of his early career studying the thermodynamics of chemical systems. He made systematic measurements of the free energy of chemical reactions. He also introduced the idea of fugacity of gases to chemical thermodynamics. This correction factor of mechanical pressure in gas reactions allows real gases to be treated as ideal gases.
Lewis added to the theory of valence bond structures using cubic atoms in his lectures. Each corner of the cube represented the position of valence electrons. His model of the atom had cubes of increasing size where the electrons filled the corners of each cube. Atoms would bond covalently by connecting one of their missing electron edges and sharing electrons to form a complete edge. This visualization would eventually be reduced to the Lewis Dot structure to show electron pairing.
This model of electron pairing led to his work with acids and bases. A Lewis acid is considered an electron pair acceptor. Lewis acids have open spots in their structures to accept an electron pair. Lewis bases, on the other hand, have an excess of electron pairs to donate in reactions. If you think of the H+ ion as a Lewis acid, it can accept an electron pair donated by the OH- Lewis base to form water. This theory expanded the known list of acids to include any ion or molecule that can accept an electron pair.
Lewis was also responsible for building the legitimacy of American chemistry. Throughout much of America’s scientific history, chemistry was a European science. Serious American students would spend a year or two in European laboratories to “legitimize” their scholarship. Lewis himself spent a couple years studying in Germany under Walther Nernst and Wilhelm Ostwald after obtaining his Ph.D. In 1912, Lewis became Dean of the College of Chemistry at the University of California, Berkeley. Under his guidance, chemistry at UC Berkeley grew over the next 32 years to be a major center of chemical study. His faculty attracted and produced multiple distinguished chemists and Nobel Prize winners. The department was home to most of the major advancements in the new field of nuclear chemistry. New and important, groundbreaking discoveries were suddenly coming from American sources and chemistry was no longer a European monopoly.
While his College of Chemistry produced many Nobel Prizes, he would never receive one himself. He was nominated 35 times for the prize but never won. Some believe it was because of an animosity that developed between Nernst and Gilbert when Gilbert studied in his lab. One of Nernst’s friends, Walther Palmaer, served on the Nobel Chemistry Committee. Palmaer nominated Lewis three times for the prize and then wrote negative reports to follow up the nomination. His student, Harold Urey won the Prize for his work on isotopes and the discovery of deuterium. Lewis contributed quite a bit to Urey’s study of heavy water that led to his discovery. Irving Langmuir would win the Nobel Prize for expanding on Lewis’ valence work which began a rivalry between the men.
Lewis died in his laboratory when an experiment with liquid hydrogen cyanide leaked gaseous hydrogen cyanide. He was found under a workbench and the coroner pronounced him dead from coronary disease. Some believe he may have committed suicide. Lewis had early had lunch with Langmuir when Langmuir visited the College to receive an honorary doctorate. After lunch, he played bridge with colleagues who said he appeared melancholic.
Notable Science History Events for October 23
2011 – Herbert Hauptman died.
Hauptman was an American mathematician and crystallographer who shares the 1985 Nobel Prize in Chemistry with Jerome Karle for their development of the direct method determining crystal structures. They found a mathematical method to determine a crystal’s molecular structure from the crystal’s x-ray diffraction pattern. This would lead to a method of three-dimensional x-ray crystallography.
1986 – Edward Adelbert Doisy died.
Doisy was an American biochemist who was awarded half the 1943 Nobel Prize in Medicine for the discovery of the chemistry of vitamin K. Vitamin K was discovered by Henrik Dam, who received the other half the Nobel Prize. Doisy isolated two different forms of the vitamin determined their structures and synthesized them. Vitamin K is used in surgery and medicine to promote blood clotting. Doisy also isolated the sex hormones estrone, estriol, and estradiol.
1944 – Charles Barkla died.
Barkla was an English physicist who was awarded the 1917 Nobel Prize in Physics for his research on x-ray transmission through matter. Barkla made numerous contributions to the study of ‘Roentgen rays’ or what we know today as X-rays. He found that each element had its own characteristic x-ray spectra. Later, this would be attributed to the transition of electrons within the atom between the lower energy levels.
1920 – Tetsuya Theodore “Ted” Fujita was born.
Fujita was a Japanese-American meteorologist who studied severe storm systems. He is best known for his Fujita scale to rate the severity of tornadoes. This scale measures tornado intensity and relates wind speed to the amount of damage the tornado causes. He is also credited with the discovery of microbursts. These powerful, short-lived bursts of air are caused by a downdraft of air that pushes outward at the ground level.
1913 – Edwin Klebs died.
Klebs was a German physician and bacteriologist who is known for his research into the bacterial theory of infection. He discovered the bacillus that causes diphtheria with Friedrich August Johannes Löffler. Diphtheria is a contagious upper respiratory disease that affects the tonsils, pharynx and nasal cavities that causes a low fever and diminished motor control and loss of sensations.
1908 – Ilya Mikhailovich Frank was born.
Frank was a Soviet physicist and shared the 1958 Nobel Prize in Physics with Pavel A. Cherenkov and Igor Y. Tamm for the discovery and theoretical explanation of Cherenkov radiation. Cherenkov radiation has a distinctive blue glow and is formed with charged particles pass through a medium where the speed of light is less than the speed the particles are moving. This discovery opened new methods of measuring the speed of relativistic particles in nuclear physics.
1905 – Felix Bloch was born.
Bloch was a Swiss physicist who shares the 1952 Nobel Prize in Physics with Edward Mills Purcell for their independent discovery of nuclear magnetic resonance (NMR). Bloch discovered NMR while investigating the magnetic properties of atomic nuclei.
Bloch also served as the first director of the European high-energy laboratory, CERN.