Answer:
1 on each compound there
Explanation:
A balanced reaction is a reaction that has the same number of atoms in the reactants and products. If this number is not the same, we need to balance it putting some numbers as coefficients behind the compound or element that needs to be balanced, For example:
NH₃ ------> N₂ + H₂
As you can see in this reaction, we have 1 nitrogen and 3 hydrogens in the reactants, and in the side of products we have 2 of each element. This needs to be balanced. To do this we put a number as coeffcient to balance the atoms. In this case, we can put a number 2 behind the NH₃, so the number of atoms of nitrogen becomes 2:
2NH₃ ------> N₂ + H₂
But this 2, changes the number of hydrogens, we now have 6 (cause 2 * 3 = 6), so, let's balance hydrogen on the products to be 6, putting a 3:
2NH₃ ------> N₂ + 3H₂
Now, the reaction is balanced in each side of the reaction.
Applying the same principle to the reaction of this exercise we have the following:
NaCl(aq) + AgNO₃(aq) ---------> AgCl(s) + NaNO₃(aq)
As you can see, we have the same number of atoms on each side:
Na: 1; Cl: 1; Ag: 1; N: 1; O: 3
So we don't need to balance this reaction, with just putting the number 1 or none, is perfectly balanced.
Hope this helps
