valency vs chemical science

valency and chemical science both are nouns.

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

valency (noun)	chemical science (noun)
(chemistry) a property of atoms or radicals; their combining power given in terms of the number of hydrogen atoms (or the equivalent)	the science of matter; the branch of the natural sciences dealing with the composition of substances and their properties and reactions
(biology) a relative capacity to unite or react or interact as with antigens or a biological substrate
the phenomenon of forming chemical bonds