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Periodic table / Transition metals

73Tantalum

Tantalum is a transition metal in group 5, period 6. At 25 °C it is a solid.

Ta
Shells: 2, 8, 18, 32, 11, 2. A simple picture: electrons do not move in circles.
Symbol
Ta
Atomic number
73 protons in the nucleus
Standard atomic weight
180.95 ± 0.01
Electron configuration
[Xe] 4f14 5d3 6s2
Electrons in each shell
2, 8, 18, 32, 11, 2
Group, period, block
5, 6, d
Family
Transition metals
State at 25 °C
solid
Electronegativity
1.5 (Pauling scale)
First ionisation energy
728.4 kJ/mol (7.549571 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.