dual vs duality

dual is not a noun while duality is a noun.

Word	Noun	Adjective	Verb	Adverb
dual	No	Yes	No	No
duality	Yes	No	No	No

dual (noun)	duality (noun)
	(physics) the property of matter and electromagnetic radiation that is characterized by the fact that some properties can be explained best by wave theory and others by particle theory
	(geometry) the interchangeability of the roles of points and planes in the theorems of projective geometry
	being twofold; a classification into two opposed parts or subclasses

dual (adjective)	duality (adjective)
consisting of or involving two parts or components usually in pairs
a grammatical number category referring to two items or units as opposed to one item (singular) or more than two items (plural)
having more than one decidedly dissimilar aspects or qualities