Search results
- Dictionarynoble gas/ˌnəʊbl ˈɡas/
noun
- 1. any of the gaseous elements helium, neon, argon, krypton, xenon, and radon, occupying Group 0 (18) of the periodic table. They were long believed to be totally unreactive but compounds of xenon, krypton, and radon are now known.
Powered by Oxford Dictionaries