Question

what is the physical change and camical change

Answer 1

In a chemical change where there is a chemical reaction, a new substance is formed and energy is either given off or absorbed.Chemical changes happen on a much smaller scale. While some experiments show obvious chemical changes, such as a color change, most chemical changes are not visible.
chemical change is permanent and irreversible

A physical change in a substance doesn't change what the substance is
A physical change is reversible, a chemical change is not. For example, the freezing of water would be a physical change because it can be reversed, whereas the burning of wood is a chemical change - you can't 'unburn' it 
 A physical change is a change in which no new substance is formed; a chemical change results in the formation of one or more new substances

Answer 2

A physical change is in which the substance doesn't change.

In a chemical change a complete new substance is formed and heat maybe liberated or absorbed.