Bohr's Quantum Research Articles

The Dielectric Constant of Atomic Hydrogen in Undulatory Mechanics

In a recent paper J. H. Van Vleck(1) used the expressions for the energy of a hydrogen atom in an electric field, derived by I. Waller(2) and the writer,(3) for computing the dielectric constant. The interesting method he applies is analogous to that used by J. H. Jones(4) for the same purpose in Bohr's quantum theory, and is outlined in section 1 of the following paper by Evelyn F. Aylesworth.(5)

XLI. Quantum defect and atomic number

1. 1. It is found that by increasing Bohr's quantum numbers for the valence electrons of elements of atomic number greater than 28, limiting quantum defects can be computed which are linear functio...

The series spectrum of ionised carbon (C II)

For the development of the theory of atomic structure there would appear to be a special need for data relating to the series spectra of the lighter elements. It has, therefore, been thought desirable to publish the present account of the series of singly-ionised carbon without waiting for the completion of the investigation of the spectrum at other stages of ionisation. It is an essential feature of Bohr's quantum theory of spectra that while the series constant for neutral atoms is nearly the same as that for hydrogen, the value of this constant will be increased four times when the atom is singly ionised, nine times when it is doubly ionised, 16 times when it is trebly ionised, and so on. Evidence that a system of series represents a particular stage of ionisation is thus to be sought in the value of the series constant for the system in question. Experimental confirmation has been obtained as far as the second ionisation by Paschen in the case of aluminium,* and as far as the third ionisation by the present writer in the case of silicon.

Some Spectrum Lines of Neutral Helium derived theoretically

IT is well known that, owing to the prohibitive nature of the general problem of three (or more) bodies, Bohr's quantum theory has proved so far to be unable to account for any spectrum lines but those forming a series of the simple Balmerian type, i.e. where N is the familiar Rydberg constant given by 2π2me4/ch3, and κ the number of unit charges contained in the nucleus, or the atomic number. Apart from X-ray spectra of the higher atoms, for which κ is replaced empirically by a smaller and not necessarily a whole number (Moseley, Sommerfeld), and where the requirements of precision are not high, this simple type of formula covers, as a matter of fact, only the spectra of atomic hydrogen (κ = 1) and of ionised helium (κ = 2), which, having been deprived of one of its electrons, presents again the same problem of two bodies as the hydrogen atom. Accordingly, the known spectrum series of He+, the ultraviolet Lyman series, the principal or Fowler's series, and the Pickering series, are all of the simple Balmer type, with n= 2, 3, 4 respectively.