Final answer:
The ionic ratio for calcium and chlorine in calcium chloride is 1:2, consistent with the formula CaCl2 where one calcium ion pairs with two chloride ions to form a neutral compound.
Step-by-step explanation:
The question is asking about the ionic ratio for calcium (Ca) and chlorine (Cl) in the compound calcium chloride. Calcium has a charge of +2 (Ca2+), and chlorine has a charge of -1 (Cl-). To form a neutral compound, two chloride ions are needed to balance the charge of one calcium ion. Therefore, the correct ionic ratio for calcium and chlorine in calcium chloride is 1:2, meaning one calcium ion to two chloride ions, which is reflected in the chemical formula CaCl2.