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