The freezing point of a substance is always lower than its melting point.

Here's why:

* Freezing is the process of a liquid changing into a solid.

* Melting is the process of a solid changing into a liquid.

These are the same physical change, just happening in opposite directions. They occur at the same temperature, which is called the freezing point (when liquid turns to solid) or the melting point (when solid turns to liquid).