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Ernest Rutherford, oil painting by J. Dunn, 1932; in the National Portrait Gallery, London. (credit: Courtesy of The National Portrait Gallery, London)

(born Aug. 30, 1871, Spring Grove, N.Z.died Oct. 19, 1937, Cambridge, Cambridgeshire, Eng.) New Zealand-born British physicist. After studies at Canterbury College, he moved to Britain to attend Cambridge University, where he worked with J.J. Thomson at the Cavendish Laboratory. He would later teach at McGill University in Montreal (18981907) and the Victoria University of Manchester (190719) before becoming chair of the Cavendish Laboratory (from 1919). At the laboratory in the years 189597, he discovered and named two types of radioactivity, alpha decay and beta decay. He later identified the alpha particle as a helium atom and used it in postulating the existence of the atomic nucleus. With Frederick Soddy he formulated the transformation theory of radioactivity (1902). In 1919 he became the first person to disintegrate an element artificially, and in 1920 he hypothesized the existence of the neutron. His work contributed greatly to understanding the disintegration and transmutation of radioactive elements and became fundamental to much of 20th-century physics. In 1908 he was awarded the Nobel Prize. He was knighted in 1914 and ennobled in 1931. Element 104, rutherfordium, was named in his honour.

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