Actinium (Ac)
Actinium is the chemical element with atomic number 89 and symbol Ac. It is a actinide in period 7, with a standard atomic weight of 227 u.
Faits essentiels
- Z
- 89
- Atomic weight
- 227 u no stable isotope
- Category
- actinide
- State at 298 K
- Solid
- Occurrence
- from decay, radioactive
- Discovered
- 1899
- CAS
- 7440-34-8
Propriétés mesurées
| Property | Value | Source |
|---|---|---|
| Electronegativity | 1.1 | National Center for Biotechnology Information (NIH) |
| Melting point | 1,324 K | National Center for Biotechnology Information (NIH) |
| Boiling point | 3,471 K | National Center for Biotechnology Information (NIH) |
| Density stp | 10.07 g/cm³ | National Center for Biotechnology Information (NIH) |
| Atomic radius empirical | 260 pm | National Center for Biotechnology Information (NIH) |
| Ionization energy 1st | 498.8 kJ/mol | National Center for Biotechnology Information (NIH) |
Configuration électronique
- Noble gas notation
- [Rn] 6d¹ 7s²
- Full notation
- 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p⁶ 6d¹ 7s²
- Electrons per shell
- 2, 8, 18, 32, 18, 9, 2