iridium vs atomic number 77

iridium and atomic number 77 both are nouns.

Word	Noun	Adjective	Verb	Adverb
iridium	Yes	No	No	No
atomic number 77	Yes	No	No	No

As nouns, iridium and atomic number 77 are synonyms defined as:

iridium and atomic number 77: a heavy brittle metallic element of the platinum group; used in alloys; occurs in natural alloys with platinum or osmium

Other synonyms of iridium include Ir.

iridium (noun)	atomic number 77 (noun)
a heavy brittle metallic element of the platinum group; used in alloys; occurs in natural alloys with platinum or osmium	a heavy brittle metallic element of the platinum group; used in alloys; occurs in natural alloys with platinum or osmium