![]() The β-radiation arising from the 'daughter' element:Ģ34 90 Th → 234 91 Pa + 0 -1β Rutherford moves to McGill ![]() The nuclear equations likely to have been involved were: 2 He named the former simply α-rays and the latter β-rays after the first two letters of the Greek alphabet, characteristic of a man who liked 'simple experiments and simple results'. Rutherford showed that two types of radiation, or 'emanation' as he called it, were involved: one that was easily absorbed and strongly ionisied the surrounding air, and another more penetrating but only weakly ionising. He placed aluminium foils of differing thicknesses above the uranium sample on A and measured the 'rate of leak' (current flowing through the ionised air) using a Thomson quadrant electrometer.įigure 1 - Schematic of Rutherford's apparatus for detecting alpha- and beta-radiation In 1897-8 Rutherford studied the radioactivity of uranium and thorium using an apparatus comprising zinc plates (A and B) 4 cm apart and charged to 50 V (see Fig 1). As Thomson's first research student, Rutherford continued his work on magnetism but, after Becquerel's discovery, soon became interested in radioactivity. Thomson (who discovered the electron in 1897). Six years later, at the age of 24, he won another scholarship, this time to Cambridge University to work with the physicist J. He won a scholarship to Canterbury College Christchurch in 1889 to study physics and mathematics, working initially on the magnetic properties of iron exposed to high-frequency radiation. Source: Library of Congress, Prints & Photographs DivisionĮrnest Rutherford was born on 30 August 1871 in Brightwater, near Nelson on the South Island of New Zealand, one of 12 children. He died at the age of 56 in Le Croisic, Brittany, on 24 August 1908. ![]() Appropriately, his name lives on as the becquerel, (Bq), the SI unit for radioactivity: one becquerel corresponds to one nuclear disintegration per second. This work later inspired Marie Curie (née Manya Sklodowska) to study radioactivity, which led her to the discovery of polonium (June 1898) and, with her husband Pierre, to the discovery of radium (December 1898).īecquerel's discovery of radioactivity earned him the Nobel prize for physics in 1903 'in recognition of the extraordinary services he has rendered by his discovery of spontaneous radioactivity' together with Pierre and Marie Curie for their work. On 2 March 1896 Becquerel announced the results of these experiments to the Académie Française. 1 He also showed that such radiation could make the surrounding air conducting. Pure uranium metal gave similar images, confirming that some type of radiation, and not light-induced phosphorescence, caused the effect. Again the images appeared, with an additional copper silhouette - he had discovered radioactivity. The next day he similarly prepared more plates and this time added a piece of copper foil, but the sun refused to shine so he kept the plates in the dark and developed them later. After developing the plates he observed faint silhouettes of the crystals on them. 2H 2 O) on top and exposed them to sunlight. ![]() He wrapped silver bromide plates in black paper, placed crystals of potassium uranyl sulfate (K 2. In 1896, inspired by Wilhelm Konrad Röntgen's discovery of x-rays, Becquerel investigated the possibility that such x-rays could cause phosphorescence and whether phosphorescent materials could emit x-rays.
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