Answer: It involves breaking molecular bonds between copper compounds.
Explanation: A physical reaction is defined as the reaction in which a change in shape, size takes place. No new substance gets formed in these reactions.
Example: melting copper, heating to high temperatures, drawing into wires
A chemical reaction is defined as the reaction in which a change in chemical composition takes place. A new substance is formed in these reactions.
Smelting is the process where metal is extracted from its ore by heating and melting. Smelting uses heat and a chemical reducing agent to decompose the ore, thus involves changes in molecular bonds and thus is chemical change.