element 111 vs atomic number 111

element 111 and atomic number 111 both are nouns.

Word	Noun	Adjective	Verb	Adverb
element 111	Yes	No	No	No
atomic number 111	Yes	No	No	No

As nouns, element 111 and atomic number 111 are synonyms defined as:

element 111 and atomic number 111: a radioactive transuranic element, with atomic number 111

Other synonyms of element 111 include Rg, roentgenium.

element 111 (noun)	atomic number 111 (noun)
a radioactive transuranic element, with atomic number 111	a radioactive transuranic element, with atomic number 111