Isotope Mass Abundance Spin Mag Moment
85Rb 84.911794 72.17% 5/2 +1.35302 87Rb 86.909187 27.83% 3/2 +2.7512
Rb I Ground State 1s22s22p63s23p63d104s24p65s 2S1/2 Ionization energy 33690.81 cm-1 (4.177128 eV) Ref. J61b Rb II Ground State 1s22s22p63s23p63d104s24p6 1S0 Ionization energy 220105.0 cm-1 (27.2895 eV) Ref. R75