chemical science vs technical-grade

chemical science is a noun but technical-grade is not a noun.

Word	Noun	Adjective	Verb	Adverb
chemical science	Yes	No	No	No
technical-grade	No	Yes	No	No

chemical science (noun)	technical-grade (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)	technical-grade (adjective)
	containing small amounts of other chemicals, hence slightly impure