NIST Physical Measurement Laboratory Handbook of Basic Atomic Spectroscopic Data

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Atomic Data for Hydrogen (H)

Atomic Number = 1

Atomic Weight = 1.00794

Reference E95


Isotope  Mass      Abundance Spin Mag Moment

1H       1.007825  99.985%   1/2  +2.79284
2H       2.0140    0.015%    1    +0.85743
Notes:

The wavelengths and energy levels given below are for the isotope 1H.

Although the tabulated energy levels comprise values for each level through n = 5, we give (Ritz) wavelengths for resolved fine structures only for the Lyman-alpha, Balmer-alpha, and Balmer-beta lines (1215, 6562, and 4861 Å). As indicated by the energy-level notations in the persistent-lines table, the other wavelengths represent unresolved multiplets. These wavelengths are from the corresponding weighted-average energies. 

 
H I  Ground State 1s  2S1/2
     Ionization energy  109678.7717 cm-1 (13.598433 eV)   Ref. MK00a