berkelium vs metallic element

berkelium and metallic element both are nouns.

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

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

berkelium: a radioactive transuranic element; discovered by bombarding americium with helium
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 berkelium include metal.

berkelium (noun)	metallic element (noun)
a radioactive transuranic element; discovered by bombarding americium with helium	any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.