Yttrium vs Actinium

PropertyY YttriumAc Actinium
Atomic number3989
SymbolYAc
NameYttriumActinium
Categorytransition-metalactinide
Standard Atomic Weight88.90584 u227 u
Period57
Group3N/A
Blockss
Phase at STPsolidsolid
Electron configuration[Kr]5s24d1[Rn]7s26d1
Oxidation states[0, 1, 2, 3][3]
Electronegativity (Pauling)1.221.1
Electron affinity0.307 eV0.35 eV
Density4470 kg/m³1.007000e+4 kg/m³
Melting point1521.85 °C1050.85 °C
Boiling point3344.85 °C3197.85 °C
Discovery year17941899