What best describes rare earth elements?, They are extremely rare in the universe, They are difficult to extract even if not geologically rare, They are only found in oceans, Which element is widely used in catalytic converters?, Cerij, Neodimij, Europij, What does “refining” mean?, Extracting raw ore from the ground, Purifying materials to obtain usable metals, Recycling old electronics only.

Klassement

Zie topspelers

Scorebord

Visuele stijl

Opties

Template wisselen

Klassement

Zie topspelers
)
Automatisch opgeslagen activiteit "" herstellen?