chemical science vs divalent

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

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

chemical science (noun)	divalent (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)	divalent (adjective)
	having a valence of two or having two valences