What is unreactive gas called?
The most common name for it is a "Noble gas"
EDIT: Also Called An "Inert Gas"
The unreactive gases are called the Noble Gases and appear in the rightmost column of the Periodic Table of the Elements. From lightest to heaviest they are:- Helium (He) Neon (Ne) Argon (Ar) Krypton (Kr) Xenon (Xe) Radon (Rn) which is radioactive. There are also a large number of unreactive gases which are compounds.