(2) That the system can pass between any two such states during emission of a homogeneous radiation.
The states in question will be denoted as “stationary states.”
The spectrum of hydrogen observed in ordinary vacuum-tubes[6] is represented by (2) and (3) by putting
Accordingly we shall assume that this spectrum is emitted by a system possessing a series of stationary states in which, corresponding to the
th state, the energy, omitting the arbitrary constant, is given by
According to Rutherford’s theory, the atom of an element consists of a central positive nucleus surrounded by electrons rotating in closed orbits. Concordant evidence, obtained in very different ways, indicates that the number of electrons in the neutral atom is equal to the number of the corresponding element in the periodic table[6].
On this theory the structure of the neutral hydrogen atom is of extreme simplicity; it consists of an electron rotating round a positive nucleus of opposite charge. In such a system we get on the ordinary mechanics the following equations for the frequency of revolution