Actinium has an atomic number of 89, meaning each atom contains 89 protons in its nucleus.
The standard atomic weight of actinium is [227] u (unified atomic mass units).
Actinium is classified as a actinide.
Actinium is a solid at 20 Β°C (68 Β°F).
The melting point of actinium is 1049.85 Β°C / 1323 K.
The boiling point of actinium is 3197.85 Β°C / 3471 K.
The density of actinium is 10.07 g/cmΒ³ (20Β°C).
Actinium has a Pauling electronegativity of 1.1.
The electron configuration of actinium is [Rn] 6d1 7s2.
Actinium commonly exhibits the following oxidation states: +3.
Actinium was discovered in 1899 by AndrΓ©-Louis Debierne.
Actinium is a naturally occurring radioactive element; all of its isotopes are radioactive.
No biological role.
Actinium is used for: Radiotherapy research; Scientific research.