You are absolutely correct! Solid copper (Cu) reacts with solid sulfur (S) to form copper sulfide (Cu₂S). This is a classic example of a synthesis reaction, where two or more reactants combine to form a single product.

Here's the balanced chemical equation for the reaction:

2Cu (s) + S (s) → Cu₂S (s)

This reaction can be carried out by heating a mixture of copper and sulfur. The copper sulfide formed is a black solid.