atomic number 21 vs Sc

atomic number 21 and Sc both are nouns.

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

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

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

Other synonyms of atomic number 21 include scandium.

atomic number 21 (noun)	Sc (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