Sc vs atomic number 21

Sc and atomic number 21 both are nouns.

Word	Noun	Adjective	Verb	Adverb
Sc	Yes	No	No	No
atomic number 21	Yes	No	No	No

As nouns, Sc and atomic number 21 are synonyms defined as:

Sc and atomic number 21: a white trivalent metallic element; sometimes classified in the rare earth group; occurs in the Scandinavian mineral thortveitite

Other synonyms of Sc include scandium.

Sc (noun)	atomic number 21 (noun)
a white trivalent metallic element; sometimes classified in the rare earth group; occurs in the Scandinavian mineral thortveitite	a white trivalent metallic element; sometimes classified in the rare earth group; occurs in the Scandinavian mineral thortveitite