The chemistry of the radio-elements / by Frederick Soddy.

  • Frederick Soddy
Date:
1914
Catalogue details

Licence: In copyright

Credit: The chemistry of the radio-elements / by Frederick Soddy. Source: Wellcome Collection.

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    present in Joachimsthal pitchblende, from which the radium was extracted. Mesothorium I, isotopic with radium, would thus be present, and would produce radio-thorium. Since radio-actinium is isotopic with radio-thorium, the absence of any indication of actinium, though radio-thorium was detected, is a guarantee that no appreciable amount of actinium can have been formed. The conclusion was reached that actinium cannot be produced from radium m Em >-&c Ac >-&c m Fig.ll. Alternative Possible Origins of Actinium. (Both now disproved). unless it has a period of at least 15 million years, which is practically impossible, as this would mean that there must be about 170 grams of it per ton of uranium in minerals, and that the a-activity of pure actinium in equilibrium with its products could never be greater than 1650 times that of uranium. It has been supposed that uranium X^, rather than uranium X^, might undergo the dual disintegration, in both modes, with expulsion of /3-rays, producing two isotopes, therefore, in group V. A, one of which would be uranium Xg, and the other the missing parent of actinium.®^ Once,
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