closed chain vs chemical chain

closed chain and chemical chain both are nouns.

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

As nouns, chemical chain is a hypernym of closed chain; that is, chemical chain is a word with a broader meaning than closed chain:

closed chain: (chemistry) a chain of atoms in a molecule that forms a closed loop
chemical chain: (chemistry) a series of linked atoms (generally in an organic molecule)

Other hypernyms of closed chain include chain.

closed chain (noun)	chemical chain (noun)
(chemistry) a chain of atoms in a molecule that forms a closed loop	(chemistry) a series of linked atoms (generally in an organic molecule)