Which Equations Are Balanced?
A)Mg (S)+ 2HCl (Aq) $\mathrm { MgCl } _ { 2 }$

Multiple Choice

Which equations are balanced?
a) Mg (s) + 2HCl (aq) ? $\mathrm { MgCl } _ { 2 }$ (aq) + $\mathrm { H } _ { 2 }$ (g)
b) 3Al (s) + 3 $\mathrm { Br } _ { 2 }$ (l) ? $\mathrm { Al } _ { 2 }$ $\mathrm { Br } _ { 3 }$ (s)
c) 2HgO (s) ? 2 Hg (l) + $\mathrm { O } _ { 2 }$ (g)

A) Only equation "c" is balanced.
B) Equations "a" and "c" are balanced.
C) Equations "b" and "c" are balanced.
D) All of them are balanced.