Soddy, Frederick (1877–1956)

English physical chemist who pioneered research into atomic disintegration and coined the term isotope. He was awarded the Nobel Prize for Chemistry in 1921 for investigating the origin and nature of isotopes.

The displacement law, introduced by Soddy in 1913, explains the changes in atomic mass and atomic number for all the radioactive intermediates in the decay processes.

After his chemical discoveries, Soddy spent some 40 years developing a theory of ‘energy economics’, which he called ‘Cartesian economics’. He argued for the abolition of debt and compound interest, the nationalization of credit, and a new theory of value based on the quantity of energy contained in a thing.

Soddy was born in Eastbourne, Sussex, and studied at Oxford. He worked 1900–02 with physicist Ernest Rutherford at McGill University in Montréal, Canada. Soddy was professor at Aberdeen 1914–19 and at Oxford 1919–36. He opposed military use of atomic power.

Soddy and Rutherford postulated that radioactive decay is an atomic or subatomic process, and formulated a disintegration law. They also predicted that helium should be a decay product of radium, a fact that Soddy proved spectrographically in 1903.

His works include Chemistry of the Radio-Elements (1912–14), The Interpretation of the Atom (1932), and The Story of Atomic Energy (1949).