roentgenium vs Rg

roentgenium and Rg both are nouns.

Word	Noun	Adjective	Verb	Adverb
roentgenium	Yes	No	No	No
Rg	Yes	No	No	No

As nouns, roentgenium and Rg are synonyms defined as:

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

Other synonyms of roentgenium include atomic number 111, element 111.

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