Answer : The spectator ions are, \(K^+,NO_3^-\)
Explanation :
In the net ionic equations, we are not include the spectator ions in the equations.
Spectator ions : The ions present on reactant and product side which do not participate in a reactions. The same ions present on both the sides.
The given balanced ionic equation will be,
\(2K_2S(aq)+Pb(NO_3)_2(aq)\rightarrow 2KNO_3(aq)+PbS(s)\)
The ionic equation in separated aqueous solution will be,
\(2K^+(aq)+S^{2-}(aq)+Pb^{2+}(aq)+2NO^{3-}(aq)\rightarrow PbS(s)+2K^+(aq)+2NO^{3-}(aq)\)
In this equation, \(K^+\text{ and }NO_3^-\) are the spectator ions.
By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.
The net ionic equation will be,
\(Pb^{2+}(aq)+S^{2-}(aq)\rightarrow PbS(s)\)