Xenon (Xe) – element 54
Xenon is a chemical element with the symbol Xe and atomic number 54. It is a noble gas in group 18 (noble gases), period 5 of the periodic table (p-block), and is a gas at room temperature.
Xenon (Xe) has atomic number 54, atomic mass 131.29 u and electron configuration [Kr] 4d10 5s2 5p6.
Xenon facts
| Symbol | Xe |
|---|---|
| Atomic number | 54 |
| Atomic mass | 131.29 u (g/mol) |
| Category | noble gas |
| Group | group 18 (noble gases) |
| Period | 5 |
| Block | p-block |
| Phase at 20 °C | Gas |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 |
| Noble-gas notation | [Kr] 4d10 5s2 5p6 |
| Electrons per shell | 2, 8, 18, 18, 8 |
| Valence electrons | 8 |
Bohr model and shells
Xenon has 54 electrons in 5 shells: 2, 8, 18, 18, 8. Full configuration and noble-gas notation are in the table; work out any element or ion with the electron configuration calculator.
Physical and atomic properties
| Melting point | 161.4 K (-111.7 °C) |
|---|---|
| Boiling point | 165.051 K (-108.1 °C) |
| Density | 5.894 g/L |
| Electronegativity (Pauling) | 2.6 |
| Electron affinity | -77 kJ/mol |
| Ionization energies | 1170.4, 2046.4, 3099.4 kJ/mol (1st, 2nd, 3rd) |
| Discovered by | William Ramsay |
Use the atomic mass in the molar mass calculator for any formula containing Xe.
Position in the periodic table
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Frequently asked questions
What is the atomic mass of xenon?
The atomic mass of xenon is 131.29 u, so one mole of xenon atoms weighs 131.29 g.
What is the electron configuration of xenon?
Xenon has 54 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶, or [Kr] 4d¹⁰ 5s² 5p⁶ in noble-gas notation. Electrons per shell: 2, 8, 18, 18, 8.
How many valence electrons does xenon have?
Xenon has 8 valence electrons (group 18).
Is xenon a metal?
No. Xenon is a nonmetal (noble gas).
Where is xenon on the periodic table?
Xenon is in group 18 (noble gases), period 5, in the p-block.
Data: Periodic-Table-JSON (CC BY-SA 3.0); standard atomic weights from IUPAC (abridged). Values in brackets are the mass number of the longest-lived isotope.