Periodic table / Lanthanoids

62Samarium

Samarium is a lanthanoid in period 6, in the lanthanoid series. At 25 °C it is a solid.

Sm
Shells: 2, 8, 18, 24, 8, 2. A simple picture: electrons do not move in circles.
Symbol
Sm
Atomic number
62 protons in the nucleus
Standard atomic weight
150.36 ± 0.02Some geological samples have an unusual isotope mix, so their atomic weight can fall outside this range.
Electron configuration
[Xe] 4f6 6s2
Electrons in each shell
2, 8, 18, 24, 8, 2
Group, period, block
–, 6, f
Family
Lanthanoids
State at 25 °C
solid
Electronegativity
1.17 (Pauling scale)
First ionisation energy
544.5 kJ/mol (5.643722 eV)
Where these numbers come from

Atomic weight: IUPAC CIAAW, abridged standard atomic weights 2024. Electron configuration and ionisation energy: NIST Atomic Spectra Database. Family, state and electronegativity: PubChem. See Sources. Melting points, boiling points and densities are left out for now: published values differ between sources, and we will add them once each has been checked.