Frederick Soddy (2.09.1877-22.09.1956) was an English physicist and chemist, one of the pioneers of radioactivity, and a Fellow of the Royal Society (1910). He was born in Eastbourne. He graduated from the University of Oxford (1898). In 1900 — 03 he worked at McGill University (Montreal), in 1903—14 at the University of Glasgow, in 1914—19 he was professor at the University of Aberdeen, and in 1919 —36 at Oxford.
His research concerned radioactivity, the chemistry of isotopes, atomic and nuclear physics, and the history of physics. Together with E. Rutherford he developed in 1902—03 the theory of radioactive decay and formulated the law of radioactive transformations. Together with W. Ramsay he proved by the method of spectroscopy in 1903 the presence of helium in the products of radium emission (the formation of helium from radon). He proved the connection between the actinium and uranium families, and discovered protactinium (1918) independently of others. He formulated (1911) the alpha rule. Independently of K. Fajans he established in 1913 the displacement rule for radioactive decay (the Soddy — Fajans law). He introduced (1913) the concept of isotopes, proved the existence of stable isotopes of lead, and predicted (1917) isomers. His work also concerned mathematics and mechanics (1921).
Nobel Prize in Chemistry (1921). A foreign corresponding member of the USSR Academy of Sciences (1924), and a member of the Royal Swedish Academy of Sciences and of the Accademia dei Lincei.