tetragen vs crystallogen

tetragen and crystallogen both are nouns.

Word	Noun	Adjective	Verb	Adverb
tetragen	Yes	No	No	No
crystallogen	Yes	No	No	No

As nouns, tetragen and crystallogen are synonyms defined as:

tetragen and crystallogen: any chemical element that belongs to the carbon group.

Other synonyms of tetragen include carbon group element, Group 14 element, tetrel.

tetragen (noun)	crystallogen (noun)
any chemical element that belongs to the carbon group.	any chemical element that belongs to the carbon group.