| Actinium | |
| Elemental State | Ac |
| Electron Configuration | 1s22s22p63s23p63d104s24p64d104f145s25p65d106s26p67s26d1 |
| First Ionization Potential | 5.17 eV |
| Electron Affinity | |
| Z* | |
| Pauling Electronegativity | 1.1 |
| Covalent Radius | |
| Metallic Radius | |
| Ionic Radius | |
| van der Waal's Radius | |
| Melting Point | 1051 oC |
| Boiling Point | 3200 oC |
| Density | 10.07 g/cm3 (calculated) |
| Other Properties | All isotopes are radioactive
227Ac half-life = 21.77 years |