corresponding to a series of configurations of the system. According to the above considerations, we are led to assume that these configurations will correspond to states of the system in which there is no radiation of energy; states which consequently will be stationary as long as the system is not disturbed from outside. We see that the value of
is greatest if
has its smallest value
. This case will therefore correspond to the most stable state of the system, i. e. will correspond to the binding of the electron for the breaking up of which the greatest amount of energy is required.
Putting in the above expressions
