Scandium vs Rubidium

PropertySc ScandiumRb Rubidium
Atomic number2137
SymbolScRb
NameScandiumRubidium
Categorytransition-metalalkali-metal
Standard Atomic Weight44.955908 u85.4678 u
Period45
Group31
Blockss
Phase at STPsolidsolid
Electron configuration[Ar]4s23d1[Kr]5s1
Oxidation states[0, 1, 2, 3][-1, 1]
Electronegativity (Pauling)1.360.82
Electron affinity0.188 eV0.4859 eV
Density2990 kg/m³1530 kg/m³
Melting point1540.85 °C39.31 °C
Boiling point2835.85 °C687.85 °C
Discovery year18791861