What is a phsical and chmical …

Physical Change: Change in which only physical properties of a substance change and no new substance is formed is called Physical Change. Most of the physical changes are reversible, this means we can get the substance back even after the change.
Examples: Folding of a paper sheet: A paper can be folded or unfolded, and hence it is an example of physical change. Moreover, no new substance is formed in this process, so it is a physical change.

Chemical changes: Changes in which chemical properties of substance change and a new substance is formed are called chemical changes. Some of the chemical changes are irreversible. Even in case of reversible changes in which chemical properties of substance change and a new substance is formed are called chemical changes. Some of the chemical changes are irreversible.
Example: Burning of wax is chemical change