chemical science vs theory of dissociation

chemical science and theory of dissociation both are nouns.

Word	Noun	Adjective	Verb	Adverb
chemical science	Yes	No	No	No
theory of dissociation	Yes	No	No	No

chemical science (noun)	theory of dissociation (noun)
the science of matter; the branch of the natural sciences dealing with the composition of substances and their properties and reactions	(chemistry) theory that describes aqueous solutions in terms of acids (which dissociate to give hydrogen ions) and bases (which dissociate to give hydroxyl ions); the product of an acid and a base is a salt and water