C. Natural selection, I've studied about this 2 years ago :)
(Also this is pretty useless to answer this late lol sorry)
the more the better and depends on what cell you need
Answer:
Mg(s) + H₂SO₄(aq) → MgSO₄(aq) + H₂(g)
Explanation:
Magnesium is a solid metal and sulfuric acid is aqueous (cuz all acids are aqueous)
When they react the salt formed is also in aqueous form and a precipitate of hydrogen is given off. hence H is a gas.
<em>Hope this helps </em>(●'◡'●)