radiocarbon vs atomic number 6

radiocarbon and atomic number 6 both are nouns.

Word	Noun	Adjective	Verb	Adverb
radiocarbon	Yes	No	No	No
atomic number 6	Yes	No	No	No

As nouns, atomic number 6 is a hypernym of radiocarbon; that is, atomic number 6 is a word with a broader meaning than radiocarbon:

radiocarbon: a radioactive isotope of carbon
atomic number 6: an abundant nonmetallic tetravalent element occurring in three allotropic forms: amorphous carbon and graphite and diamond; occurs in all organic compounds

Other hypernyms of radiocarbon include C, carbon.

radiocarbon (noun)	atomic number 6 (noun)
a radioactive isotope of carbon	an abundant nonmetallic tetravalent element occurring in three allotropic forms: amorphous carbon and graphite and diamond; occurs in all organic compounds