technical grade vs chemical science

technical grade is not a noun while chemical science is a noun.

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

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

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