a colorless and odorless inert gas; one of the six inert gases; comprises approximately 1% of the earths atmosphere
[ Syn: ar , ar , atomic number 18 , atomic number 18 ]
a colorless and odorless inert gas; one of the six inert gases; comprises approximately 1% of the earths atmosphere
[ Syn: ar , ar , atomic number 18 , atomic number 18 ]