The net ionic equation for formation of an aqueous solution of NiI 2 accompanied by evolution of CO 2 gas via mixing solid NiCO 3 and aqueous hydriodic acid is . 2NiCO3 (s) HI (aq) 2H2O (l) CO2 (g) 2Ni2 (aq) NiCO3 (s) I- (aq) 2H2O (l) CO2 (g) Ni2 (aq) HI (aq) NiCO3 (s) 2H (aq) H2O (l) CO2 (g) Ni2 (aq) NiCO3 (s) 2HI (aq) 2H2O (l) CO2 (g) NiI2 (aq) NiCO3 (s) 2HI (aq) H2O (l) CO2 (g) Ni2 (aq) 2I- (aq)

Explanation:

Spectator ions are defined as the ions which does not get involved in a chemical equation or they are ions which are found on both the sides of the chemical reaction present in ionic form.

The balanced chemical equation will be:

The total ionic chemical equation will be:

The ions which are present on both the sides of the equation are iodide ions and hence are not involved in net ionic equation.

i believe it is-

d.) gravity pulled particles of dust and gas together to form planets.