Ernest Rutherford

Ernest Rutherford

1. Who Was He?

   • Ernest Rutherford (1871–1937) was responsible for a remarkable series of discoveries in the fields of radioactivity and nuclear physics. He discovered alpha and beta rays, set forth the laws of radioactive decay, and identified alpha particles as helium nuclei.
   • He received the Nobel Prize in chemistry for 1908; he was made a knight, then a peer with a seat in the House of Lords; and for the ultimate honor he was buried in Westminster Abbey.
   • Born on a farm in New Zealand, the fourth of 12 children, Rutherford completed a degree at the University of New Zealand and began teaching unruly schoolboys.

2. What did they Find?

   • Ernest Rutherford and his team found that most of the mass and all the positive charge of the atom was in a tiny central nucleus. So, for many years we have known that atoms themselves are made up of smaller particles. The complete picture is still being built up in 'atom smashers' such as the one at CERN, near Geneva

3. What was his Experiment?

   • Along with Hans Geiger and Ernest Marsden in 1909, he carried out the Geiger–Marsden experiment, which demonstrated the nuclear nature of atoms by deflecting alpha particles passing through a thin gold foil.
   • Rutherford was inspired to ask Geiger and Marsden in this experiment to look for alpha particles with very high deflection angles, of a type not expected from any theory of matter at that time. Such deflections, though rare, were found. It was Rutherford's interpretation of this data that led him to formulate the Rutherford model of the atom in 1911 – that a very small charged nucleus, containing much of the atom's mass, was orbited by low-mass electrons.
   • He had discovered peculiar radiations when alphas were projected into air, and narrowed the effect down to the nitrogen, not the oxygen in the air. Using pure nitrogen, Rutherford used alpha radiation to convert nitrogen into oxygen through the nuclear reaction 14N + α → 17O + proton.

4. Diagram of What Was Found

Bilder und Dateien der Mindmap