Where are noble gases used? give an example

Noble gases occupy the last group of the periodic table. They are composed of helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe) and radon (Rn). These are all non-metallic elements and colorless gases at room temperature and pressure. The very inertness of noble gases is an important feature of their practical use. Helium is much less dense (lighter) than air and is used in balloons. Helium is less soluble in water than nitrogen. When inhaled, it dissolves in the bloodstream in smaller quantities than nitrogen. For this reason, a mixture of helium and oxygen is used instead of natural air for divers and others working under high air pressure. Neon is used in the familiar “neon sign” used in advertising. Argon is used in incandescent lamps because the metal filament will not burn in argon. Xenon is used in fluorescent lamps and lasers. Radon is radioactive and used in medicine as a source of gamma rays.