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61 - Promethium lanthanide

Discovered by Chien Shiung Wu in 1945

Promethium

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.
Shell Electrons Orbitals
1 2 2 in 1s
2 8 2 in 2s + 6 in 2p
3 18 2 in 3s + 6 in 3p + 10 in 3d
4 23 2 in 4s + 6 in 4p + 10 in 4d + 5 in 4f
5 8 2 in 5s + 6 in 5p
6 2 2 in 6s
PromethiumPm Electron 1 Electron 2 Electron 1 Electron 2 Electron 3 Electron 4 Electron 5 Electron 6 Electron 7 Electron 8 Electron 1 Electron 2 Electron 3 Electron 4 Electron 5 Electron 6 Electron 7 Electron 8 Electron 9 Electron 10 Electron 11 Electron 12 Electron 13 Electron 14 Electron 15 Electron 16 Electron 17 Electron 18 Electron 1 Electron 2 Electron 3 Electron 4 Electron 5 Electron 6 Electron 7 Electron 8 Electron 9 Electron 10 Electron 11 Electron 12 Electron 13 Electron 14 Electron 15 Electron 16 Electron 17 Electron 18 Electron 19 Electron 20 Electron 21 Electron 22 Electron 23 Electron 1 Electron 2 Electron 3 Electron 4 Electron 5 Electron 6 Electron 7 Electron 8 Electron 1 Electron 2
145  u Atomic Mass
2.6  Å Atomic Radius
3273  K Boiling Point
1.99  Å Covalent Radius
7.26  g/cm³ Density
12.45 Electron Affinity
1.13 Electronegativity
5.58  eV First Ionization Energy
1204.15  K Melting Point
6 Number of Shells
61 Atomic Number
2, 8, 18, 23, 8, 2 Electron Shell Occupations