Xenon (Xe): electron configuration, atomic mass and facts
Xenon (Xe) is element 54 of the periodic table, a noble gas in period 5, group 18. Its electron configuration is [Kr] 4d10 5s2 5p6, with electrons arranged in shells 2, 8, 18, 18, 8, and its standard atomic weight is 131.29 u.
▶ Watch Xenon’s electrons orbit in the interactive periodic tableXenon at a glance
| Symbol | Xe |
|---|---|
| Atomic number | 54 |
| Atomic mass | 131.29 u |
| Category | Noble gas |
| Group | 18 |
| Period | 5 |
| Block | p-block |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 |
| Noble-gas shorthand | [Kr] 4d10 5s2 5p6 |
| Electrons per shell | 2, 8, 18, 18, 8 |
| Outer-shell electrons | 8 |
| Electronegativity (Pauling) | 2.6 |
| State at 20 °C | gas |
Where is Xenon on the periodic table?
Xenon is in period 5, group 18, in the p-block. The period number matches its 5 electron shells, and the block names the subshell its last electrons fill. In the same group, Krypton sits directly above it and Radon sits directly below it. Elements in one group have the same number of outer-shell electrons (8 here), which is why they react in similar ways.
How to work out the electron configuration of Xenon
Put 54 electrons into subshells in order of rising energy, filling each before starting the next: 1s² (2), 2s² (4), 2p⁶ (10), 3s² (12), 3p⁶ (18), 4s² (20), 3d¹⁰ (30), 4p⁶ (36), 5s² (38), 4d¹⁰ (48), 5p⁶ (54). In shorthand, [Kr] stands for the 36 electrons of krypton, giving [Kr] 4d¹⁰ 5s² 5p⁶.
How electronegative is Xenon?
Xenon has a Pauling electronegativity of 2.6, ranking 8 of the 100 elements with a known value (fluorine is highest at 3.98). That is high: it pulls shared electrons strongly towards itself in a bond.
Frequently asked questions
What is the electron configuration of Xenon?
The electron configuration of Xenon (Xe) is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6. In noble-gas shorthand it is written [Kr] 4d10 5s2 5p6.
How many electrons does Xenon have in each shell?
Xenon has 54 electrons arranged in shells as 2, 8, 18, 18, 8. It has 8 electrons in its outer shell.
What is the atomic mass of Xenon?
The standard atomic weight of Xenon is 131.29 u, so one mole of Xenon atoms has a mass of about 131.29 g.
Is Xenon a metal?
No. Xenon is a noble gas.
Explore nearby elements
More noble gass: Helium, Neon, Argon, Krypton, Radon, Oganesson. See all elements on the periodic table.