### Atomic Data for Actinium (Ac)

### Atomic Number = 89

### Atomic Weight = (227)

### Reference = E95

    Isotope    Mass        Abundance Spin Mag Moment

    227Ac      227.027750  Trace     3/2  -1.1
    228Ac      228.031015  Trace     3

    Ac I  Ground State 1s22s22p63s23p63d104s24p64d104f145s25p65d106s26p66d7s2  2D3/2
          Ionization energy  41700 cm-1 (5.17 eV)   Ref. S74

    Ac II Ground State 1s22s22p63s23p63d104s24p64d104f145s25p65d106s26p67s2  1S0
          Ionization energy  94800 cm-1 (11.75 eV)   Ref. MHRS74