ERNEST RUTHERFORD (1871 – 1937 C.E.)

Ernest Rutherford, 1st Baron Rutherford of Nelson was a New Zealand chemist who has become known as the “father of nuclear physics”. In 1911, he was the first to discover that atoms have a small charged nucleus surrounded by largely empty space, and are circled by tiny electrons, which became known as the Rutherford model (or planetary model) of the atom. He is also credited with the discovery of the proton in 1919, and hypothesized the existence of the neutron. He was awarded the Nobel Prize in Chemistry in 1908 “for his investigations into the disintegration of the elements, and the chemistry of radioactive substances”. 

In 1908, Ernest Rutherford proved Thomson's atomic model to be incorrect. He is famous for his gold foil experiment which stated the existence of protons. He shot alpha particles at the gold foil, and observed where they hit. Most were undeflected, while the rest bounced off in different directions.

In 1907, Rutherford was appointed professor of physics at the University of Manchester, England. He directed Hans Geiger and Ernest Marsden in the famous Geiger-Marsden experiment (or “gold-foil experiment”) in 1909, which demonstrated the nuclear nature of atoms. It was his interpretation of these experiments in 1911 that led him to the Rutherford model of the atom, involving a very small positively-charged nucleus orbited by even tinier negatively-chargedelectrons, a great advance on J. J. Thomson’s so-called “plum pudding” model.

During Rutherford’s investigation of radioactivity at Cambridge, he invented an ingenious detector for electromagnetic waves, and coined the terms “alpha” and “beta” to describe the two distinct types of radiation emitted by thorium and uranium.