Rubidium vs Hafnium

PropertyRb RubidiumHf Hafnium
Atomic number3772
SymbolRbHf
NameRubidiumHafnium
Categoryalkali-metaltransition-metal
Standard Atomic Weight85.4678 u178.49 u
Period56
Group14
Blockss
Phase at STPsolidsolid
Electron configuration[Kr]5s1[Xe]6s24f145d2
Oxidation states[-1, 1][-2, 0, 1, 2, 3, 4]
Electronegativity (Pauling)0.821.3
Electron affinity0.4859 eV0.178 eV
Density1530 kg/m³1.330000e+4 kg/m³
Melting point39.31 °C2232.85 °C
Boiling point687.85 °C4602.85 °C
Discovery year18611911