atomic number 63 vs Eu

atomic number 63 and Eu both are nouns.

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

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

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

Other synonyms of atomic number 63 include europium.

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