quantal vs quantum

quantal is not a noun while quantum is a noun.

Word	Noun	Adjective	Verb	Adverb
quantal	No	Yes	No	No
quantum	Yes	No	No	No

quantal (noun)	quantum (noun)
	(physics) the smallest discrete quantity of some physical property that a system can possess (according to quantum theory)
	a discrete amount of something that is analogous to the quantities in quantum theory

quantal (adjective)	quantum (adjective)
of or relating to a quantum or capable of existing in only one of two states