Here's why:

* Ca (Calcium) is a metal.

* Cl (Chlorine) is a nonmetal.

When a metal and a nonmetal react, they form an ionic compound. In this case, calcium (Ca) loses two electrons to form a positively charged ion (Ca²⁺), and chlorine (Cl) gains one electron to form a negatively charged ion (Cl⁻). The electrostatic attraction between these oppositely charged ions forms the compound CaCl₂ (Calcium chloride).