Chromium vs Rubidium

PropertyCr ChromiumRb Rubidium
Atomic number2437
SymbolCrRb
NameChromiumRubidium
Categorytransition-metalalkali-metal
Standard Atomic Weight51.9961 u85.4678 u
Period45
Group61
Blockss
Phase at STPsolidsolid
Electron configuration[Ar]3d54s1[Kr]5s1
Oxidation states[-4, -2, -1, 0, 1, 2, 3, 4, 5, 6][-1, 1]
Electronegativity (Pauling)1.660.82
Electron affinity0.675 eV0.4859 eV
Density7150 kg/m³1530 kg/m³
Melting point1906.85 °C39.31 °C
Boiling point2670.85 °C687.85 °C
Discovery year17971861