For a balance chemical equation:
The number of atoms of a molecule should remain conserved that is total number of atom of a molecule in reactant side should equal to the number of atoms of a molecule in the product side.
Here also the number of atoms of an element should remain conserved on both sides, So the answer is option B.
That is
B) 3CuCl₂ + 2Al ---> 2AlCl₃ + 3Cu
Here the number of atoms of Cu, Cl and Al are equal in both side , reactant as well as product.
