* No new substance is formed: When wax melts, it simply changes from a solid state to a liquid state. The chemical composition of the wax molecules remains the same.

* The change is reversible: You can solidify the melted wax back into its original form by cooling it down. This indicates that the change is not permanent.

* No chemical bonds are broken or formed: Melting involves overcoming the intermolecular forces holding the wax molecules together, but it doesn't alter the bonds within the molecules themselves.

In contrast, a chemical change would involve the formation of new substances with different chemical compositions. For example, burning wax would be a chemical change because it produces carbon dioxide, water, and other products.