89
Ac
Actinium
Actinide period 7 f-block discovered: 1899
As a chemical element
Properties of the atom — they do not depend on what substance it is part of.
- Atomic number
- 89
- Atomic mass
- 227.02775 a.m.u.
- Electron configuration
- [Rn]7s2 6d1
- Electronegativity
- 1.1 on the Pauling scale
- Atomic radius
- 260 pm
- Ionization energy
- 5.17 eV
- Oxidation states
- +3
As a simple substance
Properties of the substance these atoms form under ordinary conditions.
- State at 25 °C
- Solid
- Melting point
- 1324 K (1 050,85 °C)
- Boiling point
- 3471 K (3 197,85 °C)
- Density
- 10.07 g/cm³