Periodic table / Noble gases
54Xenon
Xenon is a noble gase in group 18, period 5. At 25 °C it is a gas.
- Symbol
- Xe
- Atomic number
- 54 protons in the nucleus
- Standard atomic weight
- 131.29 ± 0.01
- Electron configuration
- [Kr] 4d10 5s2 5p6
- Electrons in each shell
- 2, 8, 18, 18, 8
- Group, period, block
- 18, 5, p
- Family
- Noble gases
- State at 25 °C
- gas
- Electronegativity
- 2.6 (Pauling scale)
- First ionisation energy
- 1170.4 kJ/mol (12.1298437 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.