Ruthenium vs Cesium

PropertyRu RutheniumCs Cesium
Atomic number4455
SymbolRuCs
NameRutheniumCesium
Categorytransition-metalalkali-metal
Standard Atomic Weight101.07 u132.905452 u
Period56
Group81
Blockss
Phase at STPsolidsolid
Electron configuration[Kr]5s14d7[Xe]6s1
Oxidation states[-4, -2, 1, 2, 3, 4, 5, 6, 7, 8][-1, 1]
Electronegativity (Pauling)2.20.79
Electron affinity1.05 eV0.4716 eV
Density1.210000e+4 kg/m³1930 kg/m³
Melting point2333.85 °C28.44 °C
Boiling point4149.85 °C670.85 °C
Discovery year18281860