Co vs atomic number 27

Co and atomic number 27 both are nouns.

Word	Noun	Adjective	Verb	Adverb
Co	Yes	No	No	No
atomic number 27	Yes	No	No	No

As nouns, Co and atomic number 27 are synonyms defined as:

Co and atomic number 27: a hard ferromagnetic silver-white bivalent or trivalent metallic element; a trace element in plant and animal nutrition

Other synonyms of Co include cobalt.

Co (noun)	atomic number 27 (noun)
a hard ferromagnetic silver-white bivalent or trivalent metallic element; a trace element in plant and animal nutrition	a hard ferromagnetic silver-white bivalent or trivalent metallic element; a trace element in plant and animal nutrition