1. (noun) any of the chemically inert gaseous elements of the helium group in the periodic table

• argonon
• inert gas

1. (noun) any of the chemically inert gaseous elements of the helium group in the periodic table

• ar
• argon
• atomic number 18
• atomic number 10
• ne
• neon
• atomic number 2
• he
• helium
• atomic number 36
• kr
• krypton
• atomic number 54
• xe
• xenon
• atomic number 86
• radon
• rn

1. (noun) any of the chemically inert gaseous elements of the helium group in the periodic table

• chemical element
• element
• gas