Cr vs atomic number 24

Cr and atomic number 24 both are nouns.

Word	Noun	Adjective	Verb	Adverb
Cr	Yes	No	No	No
atomic number 24	Yes	No	No	No

As nouns, Cr and atomic number 24 are synonyms defined as:

Cr and atomic number 24: a hard brittle multivalent metallic element; resistant to corrosion and tarnishing

Other synonyms of Cr include chromium.

Cr (noun)	atomic number 24 (noun)
a hard brittle multivalent metallic element; resistant to corrosion and tarnishing	a hard brittle multivalent metallic element; resistant to corrosion and tarnishing