Answer:
Total ionic equation = Ni²⁺ + 2Cl⁻¹ + 2Na⁺ + CO₃⁻² → 2Na⁺ + 2Cl⁻¹ + NiCO₃ (s)
Net ionic equation = Ni²⁺ + CO₃⁻² → NiCO₃ (s)
NiCl₂ (aq) + Na₂CO₃ (aq) → 2NaCl (aq) + NiCO₃ (s)
First, we'll need to expand the complete chemical equation into a total ionic equation (to determine whether a chemical is aqueous or solid, use a solubility chart until the rules are memorized).
Ni²⁺ + 2Cl⁻¹ + 2Na⁺ + CO₃⁻² → 2Na⁺ + 2Cl⁻¹ + NiCO₃ (s)
Now, using the total ionic equation, we can find the net ionic equation. In order to do this, we need to cancel out the aqueous solutions that don't form into solids, as they are extraneous.
Ni²⁺ + 2Cl⁻¹ + 2Na⁺ + CO₃⁻² → 2Na⁺ + 2Cl⁻¹ + NiCO₃ (s)
Ni²⁺ + CO₃⁻² → NiCO₃ (s)
I hope this helped!