beryllium vs atomic number 4

beryllium and atomic number 4 both are nouns.

Word	Noun	Adjective	Verb	Adverb
beryllium	Yes	No	No	No
atomic number 4	Yes	No	No	No

As nouns, beryllium and atomic number 4 are synonyms defined as:

beryllium and atomic number 4: a light strong brittle grey toxic bivalent metallic element

Other synonyms of beryllium include Be, glucinium.

beryllium (noun)	atomic number 4 (noun)
a light strong brittle grey toxic bivalent metallic element	a light strong brittle grey toxic bivalent metallic element