Verified answer

The groups. Theres group 1A 2A 3A 4A 5A 6A 7A 8A. 1A elements have charge of +1 2A-2+ 3A-3+ 4A-4+ or 4- 5A is 3- 6A is 2- 7A is 1-.

Now Since carbon is in group 4A it has 4+ charge. Cl is in group 7A which has a 1- charge. So when your making formulas you change the charges into coefficient and swap them to each element. So The carbons charge will turn into a 4 coefficient for CL and the CL 1- will show nothing infront of carbon. hope this helped.