Physical change – The type of change in which the physical properties of a material change. It can be changed in shape, state of matter, colour, density, size, odour, solubility, etc. During this change, only the physical traits of the substances are changed.
Chemical change – A substance is said to undergo a chemical change when the chemical properties of a substance alter. As a result, there is either formation or breaking of atomic bonds at the molecular level.
(a) Making sugar solution is a Physical change.
(b) A physical change is generally reversible.
(c) Grinding of wheat grain changes its size. It is a physical change.
(d) Iron benches kept in lawns and gardens get rusted. It is a chemical change because a new substance is formed.