Question

place the coefficients into the underlined spaces to balance the chemical equation. not all coefficients must be used and some may be used more than once.
_ agno₃ (aq)+ _ zn (s)→ _ ag (s)+ _ zn(no₃)₂ (aq)
1 2 3

Explanation:

Step1: Balance nitrate ions

On the right - hand side, there are 2 nitrate ions in $Zn(NO_3)_2$. So, we need 2 moles of $AgNO_3$ on the left - hand side to balance the nitrate ions.
$2AgNO_3(aq)+Zn(s)\longrightarrow Ag(s)+Zn(NO_3)_2(aq)$

Step2: Balance silver atoms

Since we have 2 silver atoms in $2AgNO_3$, we need 2 moles of $Ag$ on the right - hand side.
$2AgNO_3(aq)+Zn(s)\longrightarrow 2Ag(s)+Zn(NO_3)_2(aq)$

Answer:

2, 1, 2, 1