Changes in Our Surroundings

•    The changes take place around us can be classified into two categories:
    *    Physical changes
    *    Chemical changes
•    Some changes can be reversed and some cannot be reversed.
•    A change may occur by heating a substance or by mixing it with some other.
•    Contraction, evaporation, expansion and melting are some type of physical changes. These changes can be reversed.
•    Most of the chemical changes are generally not reversed.
•    The milk changing into curd is an irreversible change.
•    Ripening of fruits, cooking of food are also the examples irreversible change.