Strontium vs Radium

PropertySr StrontiumRa Radium
Atomic number3888
SymbolSrRa
NameStrontiumRadium
Categoryalkaline-earth-metalalkaline-earth-metal
Standard Atomic Weight87.62 u226 u
Period57
Group22
Blockss
Phase at STPsolidsolid
Electron configuration[Kr]5s2[Rn]7s2
Oxidation states[1, 2][2]
Electronegativity (Pauling)0.950.9
Electron affinity0.052 eV0.096 eV
Density2640 kg/m³5000 kg/m³
Melting point776.85 °C699.85 °C
Boiling point1381.85 °C1139.85 °C
Discovery year17921898