| Atomic Number: | 89 |
| Element Symbol: | Ac |
| Element Name: | Actinium |
| Atomic Weight: | 227 |
| Group Name: | Actinoid |
| Period Number: | 7 (actinoid) |
| Block: | f-block |
| Ground State Configuration: | [Rn] 6d 7s2 |
| Ground State Level: | 2D3/2 |
| Standard State: | Solid |
| Bond Length: | 375.6 |
| Atomic Radius Empirical: | 195 |
| First Ionization Energy: | 499 |
| Pauling Electronegativity: | 1.1 |
| Allred Rochow Electronegativity: | 1.00 |
| Density Of Solid: | 10070 |
| Molar Volume: | 22.55 |
| Melting Point: | 1050 |
| Boiling Point: | 3300 |
| Thermal Conductivity: | 12 |
| Enthalpy Of Fusion: | 14 |
| Enthalpy Of Vaporization: | 400 |
| Enthalpy Of Atmization: | 406 |
| Most Common Oxidation Numbers: | 3 |
| Color: | Silvery |
| Classification: | Metallic |
| Discovered By: | Andre Debierne |
| Discovered At: | France |
| Discovered When: | 1899 |
| Origin Of Name: | From the Greek word aktinos meaning ray |
Calculate the molecular weight of Actinium or molecular weight Ac.
Also see the full list of chemical elements and atomic weights.