Holdings for Helium

Symbol:	He
Atomic Weight:	4.002602(2)
Ionization Energy:	24.5874 eV
Ground-state Configuration:	1s2
Ground-state Level:	1S0

Neutral Ionization       Excitation     Total Differential 1s2 -> 1s2p 1s2 -> 1s3p 1s2 -> 1s4p 1s2 -> 1s5p 1s2 -> 1s6p 1s2 -> 1s7p 1s2 -> 1s8p 1s2 -> 1s9p 1s2 -> 1s10p

Excitation Energies (E) in eV Excitation E 1s2-1s2p 21.2180 1s2-1s3p 23.0870 1s2-1s4p 23.7421 1s2-1s5p 24.0458 1s2-1s6p 24.2110 1s2-1s7p 24.3108 1s2-1s8p 24.3755 1s2-1s9p 24.4199 1s2-1s10p 24.4517