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Radioactivity of Potassium



KLEMPEKER1 has recently shown that postulation of the existence of a radioactive isotope, 19K40, with a large nuclear spin, affords the most likely explanation of the radioactivity of potassium. He appears, however, to have over-estimated the value of the nuclear spin (i = 4 or 5 units) necessary to obtain a sufficiently high half-value period for the isotope. Klemperer made use of a statement due to Gamow2, which was based on theoretical reasoning. The latter author reached the conclusion that, if two radio-active elements possess the same upper velocity limit in their -ray spectra, and if one of them suffers unit change in nuclear spin during decay while the other preserves its spin unchanged, then the ratio of their half-value periods is about 100.

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  1. 1

    Proc. Roy. Soc., 148, 638; 1935.

  2. 2

    Phys. Z., 35, 540; 1934.

  3. 3

    Proc. Roy. Soc., 139, 659; 1932.

  4. 4

    NATURE, 135, 96, Jan. 19, 1935.

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