What is the ionic equation for the reaction of dilute hydrochloric acid and magnesium metal?

First write the “molecular” equation

Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)

Now write the ionic equation which shows anything that can dissociate , as ions .

Mg(s) + 2H+(aq) + 2Cl-(aq) → Mg2+ (aq) + 2Cl-(aq) + H2(g)

And finally write the net ionic equation . Delete anything that is common to both sides of the ionic equation . What remains is the net ionic equation

Mg(s) + 2H+ (aq) → Mg2+ (aq) + H2(g)