Give examples to explain the difference between changes that can or cannot be reversed.

(A) Changes that can be reversed:

(I) Writing with a pencil.

(II) Switching on or off of the fan.

(III) Making ice from water.

(IV) Inflating a balloon


(B) Changes then can not be reversed:

(I) Writing with a pen.

(II) Making curd from milk.

(III) Burning of paper.

(IV) Ripening of fruit