Question

which of these elements is a transition metal? mercury arsenic barium magnesium

Explanation:

Transition metals are in groups 3 - 12 of the periodic table. Mercury (Hg) is in group 12 and is a transition metal. Arsenic (As) is a metalloid, barium (Ba) is an alkaline - earth metal, and magnesium (Mg) is also an alkaline - earth metal.

Answer:

mercury