bivalent vs chemical science

bivalent is not a noun while chemical science is a noun.

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

bivalent (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

bivalent (adjective)	chemical science (adjective)
used of homologous chromosomes associated in pairs in synapsis
having a valence of two or having two valences