chemical science vs reactive

chemical science is a noun but reactive is not a noun.

Word	Noun	Adjective	Verb	Adverb
chemical science	Yes	No	No	No
reactive	No	Yes	No	No

chemical science (noun)	reactive (noun)
the science of matter; the branch of the natural sciences dealing with the composition of substances and their properties and reactions

chemical science (adjective)	reactive (adjective)
	participating readily in reactions
	reacting to a stimulus