Issuu on Google+

Ernest Rutherford’s Research on the Transformation of Atoms Ernest Rutherford was a New Zealand-born British physicist who became the ‘father of nuclear physics’. One of 12 children, he was born in 1871 in the country town of Spring Grove in Nelson and studied at Canterbury College, University of New Zealand. After college, he won a scholarship to study at Cambridge University in England which turned out to be a turning point in his life and the start of a long, productive, and influential career in atomic physics. Rutherford studied at Trinity College, Cambridge, as a research student at the Cavendish Laboratory under J.J. Thompson – who would later discover the electron. At Cambridge he found that all known radioactive elements emit two kinds of radiation: positively and negatively charged. In 1898 Rutherford accepted a professorship at McGill University in Montreal, Canada. There, he named the two types of radiation; alpha and beta rays and indicated some of their properties. He also showed that every radioactive element decreases in radioactivity over a unique and regular time, or half-life, ultimately becoming stable. Together with R.B. Owens he studied the "emanation" of thorium and discovered a new noble gas, an isotope of radon, which was later to be known as thoron. Rutherford was joined by Frederick Soddy (Winner of Nobel Prize in Chemistry 1921) at McGill’s physics department. Together they explained that radioactivity is due to the transmutation of elements, now known to involve nuclear reactions. They proved that atoms of one radioactive element would spontaneously turn into another, by expelling a piece of the atom at high velocity. Many scientists at the time scorned the idea and stuck with the age-old belief that the atom is indivisible and unchangeable. But by 1904 Rutherford's publications and achievements gained worldwide recognition. Rutherford's conclusion that atoms could be transformed and that each atom potentially carried a tremendous amount of energy earned him the Nobel Prize for Chemistry in 1908. He was awarded the prize for his research into the ‘disintegration of the elements and the chemistry of radioactive substances.' Rutherford often told his friends, the fastest transformation he knew of was his transformation from a physicist to a chemist. Rutherford returned to England to the University of Manchester in 1907. At Manchester, Rutherford teamed up with Hans Geiger to research the properties of radium emanation and alpha rays. In 1909 Rutherford made his most significant contribution to science yet, he discovered the atomic nucleus and developed the model of the atom. His atomic theory describes the atom as having a central positive nucleus surrounded by negative orbiting electrons. This model – after later improvements – is still used today to explain atomic theory. During his last year at Manchester, Rutherford discovered that the nuclei of certain light elements, such as nitrogen, could be ‘disintegrated’ by the impact of energetic alpha particles coming from some radioactive source, and that during this process fast protons were emitted. Rutherford left his research briefly during World War I to help the British Admiralty with submarine detection, but he was soon back in the lab. Resuming his work on radioactivity, he discovered that by bombarding light atoms with alpha rays and changing nitrogen into oxygen, it was possible to split the atom.

In 1919, Ernest took over as the director of the Cavendish Laboratory. There he mentored numerous future Nobel Prize winners: Chadwick, Blackett, Cockcroft and Walton. His warm, out-going personality made him an outstanding mentor. Rutherford remained active and working to the end of his life, he passed away in 1937 aged 66 – two years after the discovery of atomic fission. He was given the high honour of burial in Westminster Abbey alongside Isaac Newton and other great British scientists. Rutherford was called a ‘second Newton’ by Albert Einstein. Upon his death, the New York Times said “he was universally acknowledged as the leading explorer of the vast infinitely complex universe within the atom, a universe that he was first to penetrate.”

Ernest Rutherford