Here's why:
* Indium has a +3 charge (In³⁺).
* Carbonate has a -2 charge (CO₃²⁻).
* To balance the charges, you need two indium ions (2 x +3 = +6) and three carbonate ions (3 x -2 = -6).
Therefore, the formula is In₂(CO₃)₃.
