Cr vs chrome

Cr and chrome both are nouns.

Word	Noun	Adjective	Verb	Adverb
Cr	Yes	No	No	No
chrome	Yes	No	Yes	No

As nouns, chrome is a hyponym of Cr; that is, chrome is a word with a more specific, narrower meaning than Cr:

Cr: a hard brittle multivalent metallic element; resistant to corrosion and tarnishing
chrome: another word for chromium when it is used in dyes or pigments

Cr (noun)	chrome (noun)
a hard brittle multivalent metallic element; resistant to corrosion and tarnishing	another word for chromium when it is used in dyes or pigments

Cr (verb)	chrome (verb)
	treat with a chromium compound
	plate with chromium