Boron vs Cesium

PropertyB BoronCs Cesium
Atomic number555
SymbolBCs
NameBoronCesium
Categorymetalloidalkali-metal
Standard Atomic Weight10.8135 u132.905452 u
Period26
Group131
Blockps
Phase at STPsolidsolid
Electron configuration[He]2s22p1[Xe]6s1
Oxidation states[-5, -1, 0, 1, 2, 3][-1, 1]
Electronegativity (Pauling)2.040.79
Electron affinity0.27972 eV0.4716 eV
Density2370 kg/m³1930 kg/m³
Melting point2074.85 °C28.44 °C
Boiling point3999.85 °C670.85 °C
Discovery year18081860