Magnesium vs Rubidium

PropertyMg MagnesiumRb Rubidium
Atomic number1237
SymbolMgRb
NameMagnesiumRubidium
Categoryalkaline-earth-metalalkali-metal
Standard Atomic Weight24.3055 u85.4678 u
Period35
Group21
Blockss
Phase at STPsolidsolid
Electron configuration[Ne]3s2[Kr]5s1
Oxidation states[0, 1, 2][-1, 1]
Electronegativity (Pauling)1.310.82
Electron affinity-0.4 eV0.4859 eV
Density1740 kg/m³1530 kg/m³
Melting point649.85 °C39.31 °C
Boiling point1089.85 °C687.85 °C
Discovery year17551861