Ir vs atomic number 77

Ir and atomic number 77 both are nouns.

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

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

Ir 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 Ir include iridium.

Ir (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