Glenn Theodore Seaborg( The American chemist, Nobel Prize in Chemistry, 1951)
Comments for Glenn Theodore Seaborg
Biography Glenn Theodore Seaborg
genus. April 19, 1912
The American chemist Glenn Theodore Seaborg was born in Ishpeminge (Michigan), in the family mechanic Herman Theodore Seaborg and Selma Oliva (Erickson) Seaborg, Swedish-born. Ten years later, S., his father, mother and sister moved to the outskirts of Los Angeles (California). In the local school, the future scientist initially did not find much interest in the sciences. That changed in high school chemistry teacher with. And at graduation in 1929,. S. gave a speech on behalf of his class. Money to study at the University of California had to earn. S. was a longshoreman, collector apricots, agricultural workers, laboratory assistant in the company producing rubber and lino Assistant. In 1934, Mr.. S. received in Los Angeles, Bachelor of Science degree in chemistry and joined the University of California at Berkeley, to engage in nuclear chemistry from the famous chemist Gilbert H. Lewis. For work on the interaction of fast neutrons with the lead with. in 1937. was awarded a doctoral degree. After that he became a researcher at the Lewis and with 1939. teaches chemistry.
Early work with. As to the impact of isotopic variations in the chemistry of the elements. Isotopes are varieties of the same element whose atoms have the same number of protons but different number of neutrons. Together with colleagues with. discovered many new isotopes of common elements. In 1934, Mr.. Italian physicist Enrico Fermi attempted to create new items that are heavier than uranium by bombarding the nucleus of uranium atoms with neutrons. Four years later, in Germany, Otto Hahn, . Fritz Strassmann and Lise Meitner, . repeating this experiment, . were bombarded by neutrons, not more severe (called transuranic) elements, . as expected, . and division (splitting) of uranium atoms into atoms of smaller mass, . accompanied by a release of huge amounts of energy,
. Meitner and Otto P. Frisch published their discovery in 1939. Their work inspired P. continued to search for transuranic elements - those in which the nucleus of an atom heavier than the nucleus of an atom of uranium, the heaviest known element at that time.
One of my colleagues S., Edwin M. McMillan, generated at the cyclotron, available at the Lawrence Radiation Laboratory, University of California at Berkeley, neutrons (directing a beam of protons from the cyclotron at the beryllium target), which are then bombarded a uranium target. McMillan noted that not all attacked by neutrons, the nucleus of uranium atoms are split with. Those nuclei that capture neutrons without undergoing cleavage, behaved as predicted by Fermi: they are subjected to beta decay, increased its atomic number (number of protons) from 92 to 93, and formed a new element. This new element was named Neptune - on behalf of the planet Neptune, whose orbit lies beyond the orbit of Uranus, in whose honor was named uranium.
In 1941, Mr.. S., McMillan, Emilio Segre, Joseph Kennedy and Arthur Wahl found that as a result of further beta decay of neptunium forms an element with atomic number 94. They named this new element plutonium - on behalf of Pluto, the furthest planet from the Sun. It was found that when bombarded with slow neutrons, the isotope plutonium-239 undergoes fission, accompanied by the release of neutrons and the release of large amounts of energy. The researchers concluded that this reaction has 'the potential to serve as a filler explosive nuclear bomb', as later spoke with. Fissionable isotope uranium-233, open from. and his colleagues at approximately the same time, is another possible source of fissile material for such weapons.
. In 1939, shortly after the outbreak of the Second World War, Albert Einstein and several other scientists have warned the U.S. government that Germany may attempt to build an atomic bomb
. In response to this possibility in 1942. was established by the Manhattan Project. In the same year 30-year-old P. takes a sabbatical year at UCLA, in order to join the Manhattan Project, working in the metallurgical laboratory of the University of Chicago. Here he was appointed head of the department, develops technologies, which would allow for large-scale separation of plutonium and uranium. This issue was of great importance, since in it the scientists had only the necessary substances micrograms (one microgram is one millionth of a gram). Addition, a large chemical affinity between plutonium and uranium makes separation of these elements is extremely difficult. S. and his colleagues have developed a new technology to conduct experiments with a small amount of radioactive material, implement, thus, the experimental method, known. now as ultramikrohimichesky analysis. Plutonium was also found in nature in very small quantities in pitchblende, uranium mica and carnotite. In 1944, Mr.. group C, has a widespread separation of plutonium from uranium and other fissionable radioactive particles. By 1945, Mr.. was obtained enough plutonium to create 2 atomic bombs that destroyed the Japanese cities of Hiroshima and Nagasaki.
Shortly before the end of the war, in 1944, with. returned to the study of chemistry of transuranic elements. Since it was possible to obtain only small amounts of necessary substances, it was important to establish a basis for prediction of chemical properties of new elements. In the periodic table, developed in 1869. Russian chemist Dmitry Mendeleyev, the chemical elements are arranged in order of increasing atomic numbers. They form the rows and columns, with elements of each individual column have similar chemical properties. Elements from the 57 th and ending with the 71-m, are closely related group, which was originally named by a group of rare earth elements, and now they are called lanthanides, C. concluded that the radioactive elements, starting with 89 th and ending with the 94-m (ie. from actinium to plutonium), represent a new series, similar to a series of lighter lanthanide. This enabled him to predict the existence of elements 95 and 96, and then open them. Separating these two elements proved so difficult that the laboratory staff jokingly called them 'pandemony' and 'derily'. When they were finally identified, the element 95 was named americium, and 96 became kyuriem (in memory of Pierre Curie and Marie Curie).
In 1946, Mr.. At the University of California at Berkeley. returned to the rank of full professor (it was awarded the scientist in 1945, when he. was on vacation), and continued study of transuranic elements in the Lawrence Radiation Laboratory. S. and his colleagues found several elements included in the new series of actinides: Berkeley (atomic number 97), californium (98), Einstein (99), farm (100), mendelevium (101) and Nobel (102). They also opened the 106-th element, now called annileksiem. The work of scientists becoming harder and harder to the extent that the elements became less stable: the number of protons and neutrons in their nuclei increased. In other words, the half-life became shorter with increasing atomic mass. Half-life element represents the time required for the collapse of half the original amount of substance. Half-life of most long-lived isotope of uranium is 4 trillion. 510 million. years. Half-life 106-element - less than a second. The short lifespan of superheavy elements prevents their synthesis by gradual addition of neutrons. Therefore, researchers have synthesized them, pushing the atomic nuclei, which are blended together before the collapse. Physicists now have theorized, . according to which the nucleus itself may consist of shells of protons and neutrons shells with possible 'islands of relative stability', . which shell, . as they say, . 'filled' ( 'closed') exactly, . the electrons in the atom are grouped into shell, . 'closed' for the chemically stable elements,
. Closure of the proton and neytronovyh shell means less radioactivity and a longer half-life. If you add in the nucleus of protons or neutrons can be achieved with closed shells, . it may be a new series of superheavy elements with a sufficiently long half-life, . for you to identify and determine their chemical properties.,
. In 1951, Mr.
. S. together with Edwin M. McMillan was awarded the Nobel Prize in Chemistry "for his discoveries in the chemistry of transuranic elements'. In his opening speech on behalf of the Royal Swedish Academy of Sciences п-.пг. Vestgren said that C. 'put down one of the most brilliant pages in the history of the discovery of chemical elements', having 'no less than four of transuranic elements'. And he added: 'The prediction of [Niels] Bohr that in the face of transuranic elements, we will have a group of substances of the same kind as in the person of rare earth metals, thus, received confirmation'.
From 1954 to 1958. S. was deputy director of Lawrence Radiation Laboratory, at the same time leading its research section of the nuclear chemistry. In 1958, Mr.. he said, refusing further conduct of research, was a three-year president of the University of California at Berkeley. In 1961. S. was appointed head of the Atomic Energy Commission. After retiring to resign from that post in 1971, he returned to Berkeley as Professor of Chemistry, University of California. His concerns about science education has meant that in 1983. He became the head of a university graduate.
In 1942, Mr.. S. married to Helen L. Griggs. In the couple have four sons and two daughters. In his spare time scientist enjoys playing golf, reading and gardening.
With. won many awards, among them the reward Enrico Fermi Atomic Energy Commission, USA (1959), Medal of the Franklin Institute Franklinovskogo (1963) and the Priestley Medal of the American Chemical Society (1979). Scientist - a member of the U.S. National Academy of Sciences, the American chemical, physical, and nuclear companies and the American Association for the Advancement of Science, as well as a foreign member of 10 national academies of sciences (in t.ch. Academy of Sciences of the USSR). He was awarded honorary degrees from more than 40 universities. A talented administrator and politician, C. participates actively in the work of many organizations related to science, education, the formation of television programs and their impact on society.