Phosphorus vs Promethium

PropertyP PhosphorusPm Promethium
Atomic number1561
SymbolPPm
NamePhosphorusPromethium
Categorynonmetallanthanide
Standard Atomic Weight30.973762 u145 u
Period36
Group15N/A
Blockps
Phase at STPsolidsolid
Electron configuration[Ne]3s23p3[Xe]6s24f5
Oxidation states[-3, -2, -1, 0, 1, 2, 3, 4, 5][2, 3]
Electronegativity (Pauling)2.19N/A
Electron affinity0.7466 eV0.129 eV
Density1820 kg/m³7260 kg/m³
Melting point44.15 °C1041.85 °C
Boiling point280.5 °C2999.85 °C
Discovery year16691902