electrons rotating in a ring round a nucleus is formed in a way analogous to the one assumed for a single electron rotating round a nucleus. It will thus be assumed that the electrons, before the binding by the nucleus, were at a great distance apart from the latter and possessed no sensible velocities, and also that during the binding a homogeneous radiation is emitted. As in the case of a single electron, we have here that the total amount of energy emitted during the formation of the system is equal to the final kinetic energy of the electrons. If we now suppose that during the formation of the system the electrons at any moment are situated at equal angular intervals on the circumference of a circle with the nucleus in the centre, from analogy with the considerations on [p. 5] we are here led to assume the existence of a series of stationary configurations in which the kinetic energy per electron is equal to
, where
is an entire number,
Planck’s constant, and
the frequency of revolution. The configuration in which the greatest amount of energy is emitted is, as before, the one in which