chemical science vs displacement reaction

chemical science and displacement reaction both are nouns.

Word	Noun	Adjective	Verb	Adverb
chemical science	Yes	No	No	No
displacement reaction	Yes	No	No	No

chemical science (noun)	displacement reaction (noun)
the science of matter; the branch of the natural sciences dealing with the composition of substances and their properties and reactions	(chemistry) a reaction in which an elementary substance displaces and sets free a constituent element from a compound