Question

what is a noble gas?

Answer 1

A noble gas has stable electronic configuration and therefore cannot give, take or share its electrons.. They come in group 18 or are also called zero group elements.
For eg. - Helium.

Answer 2

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.