Meaning of ATOMIC NUMBER 2

WordNet Dictionary
	Definition:		[n]  a very light colorless element that is one of the six inert gasses; the most difficult gas to liquefy; occurs in economically extractable amounts in certain natural gases (as those found in Texas and Kansas)
	Synonyms:		He, helium
	See Also:		argonon, chemical element, element, inert gas, noble gas