* No new substance is formed: When a metal melts, it changes from a solid state to a liquid state. The chemical composition of the metal remains the same. It's still the same metal atoms arranged differently.

* Change is reversible: You can solidify the molten metal by cooling it down, returning it to its original solid form. This reversibility is a key characteristic of physical changes.

Contrast this with a chemical change:

* New substance formed: Burning a piece of metal (like iron) is a chemical change because it reacts with oxygen to form iron oxide (rust), a completely different substance.

* Change is irreversible: Rusting is difficult to reverse, requiring significant chemical processes.

In summary: Melting a metal is a physical change because it only alters the state of matter, not the chemical composition.