Krypton vs Ruthenium

PropertyKr KryptonRu Ruthenium
Atomic number3644
SymbolKrRu
NameKryptonRuthenium
Categorynoble-gastransition-metal
Standard Atomic Weight83.798 u101.07 u
Period45
Group188
Blockps
Phase at STPgassolid
Electron configuration[Ar]4s23d104p6[Kr]5s14d7
Oxidation states[0, 1, 2][-4, -2, 1, 2, 3, 4, 5, 6, 7, 8]
Electronegativity (Pauling)32.2
Electron affinity-1 eV1.05 eV
Density3.733 kg/m³1.210000e+4 kg/m³
Melting point-157.36 °C2333.85 °C
Boiling point-153.42 °C4149.85 °C
Discovery year18981828