Question

what is physical and chemical change? Explain properly.

Answer 1

the change in which substance can be reverse by changing their state is physical change.

for example:- mixture of sugar and water.

here sugar and water both can be separate again by process of evaporation.

while

the process in which substance can not be reverse by changing their state is called chemical change.

for example:- rusting of iron , burning of paper.

here paper or iron can not be obtain again.

hope it helps u......!!!

Answer 2

Physical change :

The change in which the physical apperance of the substances like size, shape changes but the chemical composition remains the same. In this change no new substance is formed and we can gain the original substance back.

Example :

Melting of ice is a physical change. In this the ice melts into water. So here the physical apperance like size and shape is changing but no chemical change is seen. Also, we can gain the original substance back by the freezing the water.

Chemical change:

The change in which a new substance is formed and the chemical composition of the substance changes. In this change gas may be evolved or bubbles may be formed. We cannot gain the original substance back.

Example :

Burning of paper is a chemical change. Here gas is evolved and also we cannot gain the original paper back.