Chromium vs Actinium

PropertyCr ChromiumAc Actinium
Atomic number2489
SymbolCrAc
NameChromiumActinium
Categorytransition-metalactinide
Standard Atomic Weight51.9961 u227 u
Period47
Group6N/A
Blockss
Phase at STPsolidsolid
Electron configuration[Ar]3d54s1[Rn]7s26d1
Oxidation states[-4, -2, -1, 0, 1, 2, 3, 4, 5, 6][3]
Electronegativity (Pauling)1.661.1
Electron affinity0.675 eV0.35 eV
Density7150 kg/m³1.007000e+4 kg/m³
Melting point1906.85 °C1050.85 °C
Boiling point2670.85 °C3197.85 °C
Discovery year17971899