Here's why:

* Physical changes involve alterations in the form or appearance of a substance, but not its chemical composition.

* Chemical changes result in the formation of new substances with different chemical properties.

When you free something, you are simply changing its position or state, not its chemical makeup. For example:

* Freeing a bird from a cage changes its location but not its species or biological properties.

* Freeing a frozen object changes its state from solid to liquid, but the chemical composition of the object remains the same.

Therefore, freeing something is a physical change because it doesn't alter the fundamental chemical nature of the substance involved.