Question

which element can biomagnify and bioaccumulate in ecosystems? mercury helium

Explanation:

Biomagnification and bioaccumulation involve substances accumulating in organisms and increasing in concentration up the food chain. Mercury is a toxic heavy metal that undergoes these processes (e.g., methylmercury in aquatic food chains). Helium is a noble gas, non - toxic, and does not biomagnify or bioaccumulate.

Answer:

Mercury