Question

19
select the correct answer.
what is the chemical formula of calcium chloride?
a. cacl
b. ca₂cl₂
c. ca₂cl
d. cacl₂

Explanation:

Step1: Determine ion charges

Calcium (Ca) is in group 2, so it forms \(Ca^{2+}\) ions. Chlorine (Cl) is in group 17, forming \(Cl^-\) ions.

Step2: Balance charges

To balance the charges, we need 2 \(Cl^-\) ions for each \(Ca^{2+}\) ion (since \(2\times(-1) + (+2) = 0\)).

Step3: Write the formula

The formula is \(CaCl_2\) (using the criss - cross method: the charge of Ca becomes the subscript of Cl, and the charge of Cl becomes the subscript of Ca, then simplify if possible).

Answer:

D. \(CaCl_2\)