europium vs metallic element

europium and metallic element both are nouns.

Word	Noun	Adjective	Verb	Adverb
europium	Yes	No	No	No
metallic element	Yes	No	No	No

As nouns, metallic element is a hypernym of europium; that is, metallic element is a word with a broader meaning than europium:

europium: a bivalent and trivalent metallic element of the rare earth group
metallic element: any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.

Other hypernyms of europium include metal.

europium (noun)	metallic element (noun)
a bivalent and trivalent metallic element of the rare earth group	any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.