Rutherford, Sir Ernest

Rutherford, Sir Ernest (1871-1937). First to prove radioactive decay of heavy elements and to carry out a transmutation reaction (1919). Discovered half-life of radioactive elements. Nobel Prize 1908. 

Sir Ernest Rutherford (1871-1937 Nobel Prize for chemistry 1908, which as a physicist he puzzled over) was a brilliant experimentalist endowed with an equal genius of being able to interpret the results. He recognized three types of radiation (alpha, beta, and gamma). He used scattering experiments with alpha radiation, which consists of helium nuclei, to prove that the atom is almost empty. The diameter of the atomic nucleus is about 10 000 times smaller than the atom itself. Furthermore, he proved that atoms are not indivisible and that in addition to protons, there must also be neutrons present in their nucleus. With Niels Bohr he developed the core-shell model of the atom. 

As concerns the spontaneous transmutations undergone by the radioactive elements, the facts appear to indicate (or, at least, can be brought into some sort of order by supposing) the atom to consist of a central nucleus and an outer shell, as suggested by Sir Ernest Rutherford. The nucleus may be compared to the sun of a solar system. It is excessively small, but in it the mass of the atom is almost entirely concentrated. It is positively charged, the charge being neutralised by that of the free electrons which revolve like planets about it, and which by their orbits account for the... 

There is also a sixth member of this series, known as uranium Y (46, 50, 56, 59), which was discovered in 1911 by G. N. Antonoff, who was working under Sir Ernest Rutherford at the University of Manchester. He afterward returned to St. Petersburg. Uranium Y, like uranium Z, belongs to a subordinate branch of the family. Frederick Soddy attributed Antonoff s success, not to the special chemical process adopted, but to the lapse of a suitable period of time between successive separations" (75). Thus in the uranium series uranium 1 breaks down to form uranium Xj, and this in turn disintegrates to form the successive products uranium X2, uranium Z, uranium 2, and uranium Y. 

Sir Ernest Rutherford was born in 1871 in Nelson, New Zealand. After studying at New Zealand University and Cambridge, he went to Canada in 1898 as a professor of physics at McGill University. After serving there for nine years and carrying out many remarkable researches in radioactivity, he became professor of physics at Manchester University, and in the following year he was awarded the Nobel Prize in chemistry. In 1919 he became a professor at Cambridge (72). 

R. B. Owens, Macdonald professor of electrical engineering at McGill University, and Sir Ernest Rutherford noticed that when a thorium compound is placed in an open vessel exposed to air currents, its radio-... 

During 1910-1911, Sir Ernest Rutherford suggested ail experiment, carried out by Geiger and Maisden, in which alpha panicles from a radioactive source were scattered from thin foils, The angles at which the alpha particles were scattered were found to be such as could best be... 

A more convincing experiment performed by Crookes [34] involved Fe(OH)3 as a carrier of uranium X (having the more convenient ti/2 = 24 days) precipitated from the soluble uranyl carbonato complex in excess (NH4)2C03. These observations show an insoluble hydroxide, but they did not establish the thorium(IV) chemistry of this Th isotope, the first descendant of Sir Ernest Rutherford (1871-1937) and Frederick Soddy (1877-1956) then showed [35] that ti 2 = 3.6 days of thorium X ( Ra), soluble in aqueous ammonia, is replaced by radio-elements precipitating as hydroxides. In 1907 Rutherford demonstrated [36] that ionium ( °Th with tj j = 80000 years, the immediate ancestor of Ra with t j = 1600 years in uranium minerals), Th (tiy2 = 14100 million years), and radiothorium Th (ti/2 = 1-9 years) cannot be separated by chemical means. 

Sir Ernest Rutherford achieves the first transmutation of an element, converting nitrogen into oxygen. 

Sir Ernest Rutherford dies on October 19 in Cambridge, England. 

Electron Orbits. The first attempt to solve the problem of the arrangement of the electrons around the nucleus was made by Sir Ernest Rutherford when he suggested that the electrons revolve round the nucleus like the planets revolve round the sun. Neils Bohr pointed out, however, that the number of orbits available for these electrons must be limited and that the electrons could only rotate in orbits in which they possess definite discrete amounts or quanta of energy thus the only orbits available would be those in which the electrons have one, two, three, four,. . . etc., quanta of energy. 

Marsden returned to his native New Zealand in 1915 where, on Rutherford s recommendation, he was appointed professor of physics at Victoria University in Wellington. Ele held various academic and governmental posts until his retirement in 1954. The national fund for the support of science in New Zealand was renamed the Sir Ernest Marsden Eund in his honor. SEE ALSO Geiger, Hans Rutherford, Ernest. 

Element 104 Rutherfordium (Rf) honoring Sir Ernest Rutherford (LBNL Berkeiey, JiNR Dubna, shared). 

British nuclear physicist Sir Ernest Rutherford (Lord... 

Sir Ernest Rutherford (U.K.) theorizes that the atom has a positive nucleus surrounded by electrons. [1911]... 

Ernest Rutherford, Frederick Soddy, and then Sir William Ramsay documented natural transformations of one element into another in 1902 and 1903. The artificial transmutation of one element into another, however, was first accomplished in 1919 by Rutherford, a physicist. Indeed, the field of nuclear physics has contributed the most to our understanding of the subatomic world since the 1920s. But the scientists who most advocated transmutation as a goal of research and a heuristic principle for understanding the nature of matter—the Nobel Prize winners Ramsay and Soddy, and, in a less prominent way, Sir William Crookes—were chemists, not physicists.1... 

By the early twentieth century, chemists and physicists recognized that the atoms of which chemical elements are composed are themselves made up of electrons and protons, of electrically negative and positive subatomic particles that were the universal constituents of all chemical elements. Sir Joseph Thomson had discovered the electron in 1897. Ernest Rutherford postulated the existence of a positive nucleus in atoms in 1911, and he used this in developing his planetary model of the atom, with a positive center and orbiting electrons. He discovered the proton in 1919, in experiments on the disintegration of atomic nuclei. Much later, in 1932, the British physicist James Chadwick (1891— 1974) discovered a third subatomic particle, the electrically neutral neutron. 

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