Here's the chemical reaction:

Cu + Cl₂ → CuCl₂

This reaction occurs because copper is a reactive metal and chlorine is a reactive non-metal. Copper readily loses electrons to form copper ions (Cu²⁺), while chlorine readily gains electrons to form chloride ions (Cl⁻). The attraction between these oppositely charged ions creates the ionic compound copper(II) chloride.

Important notes:

* The reaction requires heat or a catalyst to initiate.

* The product, copper(II) chloride, is a brown solid that is soluble in water.

* The reaction is a classic example of a redox reaction, where copper is oxidized and chlorine is reduced.