chemical chain vs chemistry

chemical chain and chemistry both are nouns.

Word	Noun	Adjective	Verb	Adverb
chemical chain	Yes	No	No	No
chemistry	Yes	No	No	No

chemical chain (noun)	chemistry (noun)
(chemistry) a series of linked atoms (generally in an organic molecule)	the science of matter; the branch of the natural sciences dealing with the composition of substances and their properties and reactions
	the way two individuals relate to each other
	the chemical composition and properties of a substance or object