The Noble Gases — Properties and Uses (He, Ne, Ar, Kr, Xe, Rn)
The noble gases sit on the far right of the periodic table in group 18. Because their outer electron shells are already complete, they barely react with anything — hence the name inert gases. That very unreactivity is what makes them useful.
Members and shared traits
Six of them: helium He, neon Ne, argon Ar, krypton Kr, xenon Xe, radon Rn (plus synthetic Og). They are monatomic gases at room temperature, colourless and odourless, with full outer shells (2 for He, 8 for the rest), very stable chemistry and very low boiling points.
Individual uses
| Gas | Main uses |
|---|---|
| Helium He | balloons/airships, cryogenic cooling of superconducting magnets, diving gas mixes |
| Neon Ne | neon signs (red glow) |
| Argon Ar | welding shield gas, filler in light bulbs and double glazing |
| Krypton Kr / Xenon Xe | high-intensity lighting, camera flashes, xenon headlights |
| Radon Rn | radioactive; mainly relevant for radiation safety (indoor radon monitoring) |
Why they are inert
Their outer shell is full, so they neither gain nor lose electrons easily and generally form no compounds (xenon makes a few fluorides under special conditions). This contrasts sharply with reactive metals and nonmetals. Browse by category in the browse view.