atomic number 63 vs europium

atomic number 63 and europium both are nouns.

Word	Noun	Adjective	Verb	Adverb
atomic number 63	Yes	No	No	No
europium	Yes	No	No	No

As nouns, atomic number 63 and europium are synonyms defined as:

atomic number 63 and europium: a bivalent and trivalent metallic element of the rare earth group

Other synonyms of atomic number 63 include Eu.

atomic number 63 (noun)	europium (noun)
a bivalent and trivalent metallic element of the rare earth group	a bivalent and trivalent metallic element of the rare earth group