Actinium
| Basic Information | Crystal Structure | Isotope | Facts | Related Links |
| Symbol: | Ac |
| Atomic Number: | 89 |
| Mass: | 227 |
| Melting Point: | 1050C |
| Boiling Point: | 3200C |
| Number of Protons/Electrons: | 89 |
| Number of Neutrons: | 138 |
| Classification: | Rare Earth |
| Crystal Structure: | Cubic |
| Density at 293 K: | 10.07 g/cm3 |
| Color: | Silvery |
| Isotope | Half Life |
| Ac-225 | 10.0days |
| Ac-226 | 1.2 days |
| Ac-227 | 21.8 years |
| Ac-228 | 6.16 hours |
| Date of Discovery: | 1899 |
| Discoverer: | Andre Debierne |
| Uses: | No uses known |
| Obtained From: | extremely rare |