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Promethium (Pm)
Atomic number: 61 · Category: lanthanide · Group 3 · Period 6 · Phase: Solid
Promethium, originally prometheum, is a chemical element with the symbol Pm and atomic number 61. All of its isotopes are radioactive; it is one of only two such elements that are followed in the periodic table by elements with stable forms, a distinction shared with technetium. Chemically, promethium is a lanthanide, which forms salts when combined with other elements.
Atomic mass: 145
Density: 7.26
Melting point: 1315 K
Boiling point: 3273 K
Appearance: metallic
Source: Wikipedia
Block: f
CPK color:#a3ffc7
Electronic structure
Electron configuration: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f5
Configuration (semantic): [Xe] 4f5 6s2
Shells: 2, 8, 18, 23, 8, 2
Electronegativity (Pauling): 1.13
Electron affinity: 12.45
Ionization energies: 540, 1050, 2150, 3970
Periodic position
Group: 3
Period: 6
xpos: 7
ypos: 9
Spectral/Bohr images
Image
3D Model