Actinium

Symbol | Ac
Latin name | Actinium
Atomic number | 89
Period | 7
Element category | Transition elements
Relative atomic mass | 227.0278
Group | III.B
Electronegativity | 1.1
Oxidation numbers | 3
Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d10 6s2 6p6 6d1 7s2
Density [g/cm3] | 10.07
State | Solid
Melting point [°C] | 1050
Boiling point [°C] | 3200
Atomic radius [pm] | 195
Thermal conductivity [W m-1K-1] | 12
Heat capacity [J K-1g-1] | 0.12
Discovery | 1899
1.st ionization energy [eV] | 5.17
2.nd ionization energy [eV] | 10.148
Stable isotopes | 0
Unstable isotopes | 11