Strontium vs Cesium

PropertySr StrontiumCs Cesium
Atomic number3855
SymbolSrCs
NameStrontiumCesium
Categoryalkaline-earth-metalalkali-metal
Standard Atomic Weight87.62 u132.905452 u
Period56
Group21
Blockss
Phase at STPsolidsolid
Electron configuration[Kr]5s2[Xe]6s1
Oxidation states[1, 2][-1, 1]
Electronegativity (Pauling)0.950.79
Electron affinity0.052 eV0.4716 eV
Density2640 kg/m³1930 kg/m³
Melting point776.85 °C28.44 °C
Boiling point1381.85 °C670.85 °C
Discovery year17921860