The Radioactivity of Potassium

Abstract

The radioactivity of K was measured with a Geiger counter by placing a thick layer of the salt under a thin Al window. The results agree with those of M\"uhlhoff and give for the radioactive constants when corrected for the relative abundance of ${\mathrm{K}}^{40}$ the following values: $\ensuremath{\lambda}=(1.56\ifmmode\pm\else\textpm\fi{}0.6)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}17}$ ${\mathrm{sec}.}^{\ensuremath{-}1}$, and $T=(14.2\ifmmode\pm\else\textpm\fi{}3.0)\ifmmode\times\else\texttimes\fi{}{10}^{+8}$ yr.