Here's why:

* Metals and Nonmetals: Copper (Cu) is a metal, and chlorine (Cl) is a nonmetal. Ionic compounds are typically formed between metals and nonmetals.

* Electrostatic Attraction: Metals tend to lose electrons to form positively charged ions (cations), while nonmetals tend to gain electrons to form negatively charged ions (anions). In CuCl, copper forms Cu+ ions and chlorine forms Cl- ions. These oppositely charged ions are held together by strong electrostatic forces, forming an ionic bond.

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