Xenon (Xe)
Noble gas · p-block · period 5 · group 18
Colourless, heavy gas; glows blue-white in a discharge tube.
Xenon (symbol Xe) is chemical element number 54, a noble gas in group 18, period 5 of the periodic table. Its standard atomic weight is 131.29 and its electron configuration is [Kr] 4d10 5s2 5p6. At room temperature it is a gas. Its name means 'the stranger'.
Properties
| Atomic number | 54 |
|---|---|
| Atomic mass | 131.29 |
| Category | Noble gas |
| Block | p-block |
| Group · Period | 18 · 5 |
| Electron configuration | [Kr] 4d10 5s2 5p6 |
| Electrons per shell | 2, 8, 18, 18, 8 |
| State at 25 °C | gas |
| Melting point | 161.4 K |
| Boiling point | 165.03 K |
| Density | 5.894 g/L |
| Electronegativity (Pauling) | 2.6 |
| Radioactive | No |
| Origin | primordial |
| Discovered | 1898 · Ramsay & Travers |
Key facts about Xenon
- Its name means 'the stranger'.
- The first noble gas shown to form a real compound (xenon tetrafluoride, 1962), overturning the idea that they never react.
- Xenon flash lamps give the brilliant white burst in camera flashes and stroboscopes.
- An effective general anaesthetic, though too expensive for routine use.
What Xenon is used for
Camera and cinema flash lamps, car headlights, ion thrusters for spacecraft, anaesthesia, medical imaging.
Where it sits in the periodic table
Xenon is in group 18, period 5, of the p-block. Its electron configuration [Kr] 4d10 5s2 5p6 means its outermost shell holds 8 electrons, which is what places it here and explains much of its chemistry. See Xenon on the interactive table →
Xenon — frequently asked questions
What is Xenon used for?
Camera and cinema flash lamps, car headlights, ion thrusters for spacecraft, anaesthesia, medical imaging.
Is Xenon radioactive?
No. Xenon has at least one stable isotope and is not radioactive.
What is the electron configuration of Xenon?
Xenon has the electron configuration [Kr] 4d10 5s2 5p6, which is 2, 8, 18, 18, 8 electrons per shell.
What group and period is Xenon in?
Xenon is in group 18, period 5, in the p-block. Its outer shell holds 8 electrons.
Who discovered Xenon?
Xenon was discovered in 1898 by Ramsay & Travers.