The formula is for 1 Calcium, 3 Magnesium, 4 Carbon, & 12 Oxygen. The 4 after the parenthesis of (CO3) distributes to each element.
Answer : There are 4 Carbon atoms in the formula.
There are 9 orbitals in the third energy level and 25 orbitals in the fifth energy level.
I hope this helps you.
