Some Facts Bearing on the Structure of Atoms, Particularly of the Helium Atom

Discussion of Suggested Models for Helium and Other Atoms in the light of recent results of a study of multiple ionization by alpha rays. As will be reported more fully elsewhere it has been found that slow alpha rays detach both electrons from some of the helium atoms through which they pass, the number of doubles being one sixth the number of singles, while in the case of the other gases tested no evidence of multiple ionization has been obtained. The result is considered by the author to indicate that the electronic orbits in the helium atom must be such as to bring the two electrons into the same part of the atomic volume at least one sixth of the time, a condition which is well satisfied by the recent models of Land\'e and Bohr in which the orbits cross each other. In the case of other atoms the new evidence favors the Bohr models, with few electrons in the outer shells.Multiple Ionization in Arcs and Sparks is Probably Due to successive ionization of the same atoms.