Radium vs Berkelium

PropertyRa RadiumBk Berkelium
Atomic number8897
SymbolRaBk
NameRadiumBerkelium
Categoryalkaline-earth-metalactinide
Standard Atomic Weight226 u247 u
Period77
Group2N/A
Blockss
Phase at STPsolidsolid
Electron configuration[Rn]7s2[Rn]7s25f9
Oxidation states[2][2, 3, 4, 5]
Electronegativity (Pauling)0.91.3
Electron affinity0.096 eV-0.5 eV
Density5000 kg/m³1.400000e+4 kg/m³
Melting point699.85 °C1049.85 °C
Boiling point1139.85 °C-273.15 °C
Discovery year18981949