Question

Which of these processes indicates that smelting copper is a chemical change? It involves melting copper to form liquid metal. It involves heating charcoal to high temperatures. It involves drawing copper into long wires. It involves breaking molecular bonds between copper compounds.

Answer 1

It involves breaking molecular bonds between copper compounds.

Answer 2

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.