* Physical changes alter the form or appearance of a substance but not its chemical composition. The molecules themselves remain the same.
* These changes are often reversible. For example, you can unbend a piece of paper, unfold a piece of fabric, and sometimes even tape a tear back together (though it might not look perfect).
Let's break down each example:
* Bending: Changes the shape of an object without altering its chemical makeup.
* Folding: Alters the form of the object by creating creases, but it doesn't change the substance itself.
* Tearing: Creates a break in the object, but the chemical composition of the material remains the same.
In contrast, chemical changes result in the formation of new substances with different chemical compositions. Examples include burning wood, rusting metal, or cooking an egg.
