Artificially Radioactive Element 85

Bismuth bombarded with 32-Mev alpha-particles becomes radioactive. Two ranges of alpha-particles are emitted, one of 6.55 cm and one of 4.52 cm. These two alpha-particles are not genetically related. There are also x-rays which show the absorption characteristics of polonium x-rays. All these radiations separate together chemically as element 85, and all show the same half-life of 7.5 hours. The probable explanation of these effects is the following: ${\mathrm{Bi}}^{209}$, by an ($\alpha ,2n$) reaction, goes to ${85}^{211}$, which decays either by $K$-electron capture to actinium C'(${\mathrm{Po}}^{211}$) or by alpha-particle emission (range 4.5 cm) to ${\mathrm{Bi}}^{207}$. The 6.5-cm alpha-particles are those of actinium C'. According to this scheme the second branch from ${85}^{211}$ leads to ${\mathrm{Bi}}^{207}$ which should decay to ${\mathrm{Pb}}^{207}$. As yet we have been unable to find this activity. We discuss the chemical properties of element 85 and show that in general its behavior is that of a metal.