chemical science vs chemist

chemical science and chemist both are nouns.

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

chemical science (noun)	chemist (noun)
the science of matter; the branch of the natural sciences dealing with the composition of substances and their properties and reactions	a scientist who specializes in chemistry
	a health professional trained in the art of preparing and dispensing drugs