How do I predict the formula for the ionic compounds when I combine?
Cr(+3) and chlorate
Na(+1) and carbonate
K(+1) andsulfate
Use the charges of the negative ions and make sure the charge of the compound equals zero.
Chlorate, carbonate and sulfate ions all have a charge of -2.
Potassium sulfate is K2SO4. Now you do the others.