Physical and chemical change

Question 1  What is a physical change.Give example?

Question 2 What is a chemical change.Give example ?

Question 3 Give the main differences between physical and chemical change?

Physical and Chemical changes

Physical changes
The changes in which no new substance are formed,are called physical changes.

In a physical change,the substances involved do not change their identity.They can be easily returned to their original form by some physical changes.

For Ex:Freezing of water,Boiling of water,Condensation of steam,Making a solution,Glowing of electric bulb,stretching of rubber band,cutting or tearing a piece of paper etc.

Chemical Changes
The changes in which new substance are formed,are called chemical changes.

In a chemical change,the substances involved change their identity ie they get converted into entirely new substance.

For Ex:Burning of magnesium ribbon,Rusting of iron,Formation of curd from milk,Cooking of food etc.

   Physical change Chemical Change
1)No new substance is formed in the physical change.A new substance is formed in a chemical change.
2)Physical change is temporary change.A chemical change is a permanent change.
3)Physical change is reversible.Chemical change is irreversible.
4)Very little heat or light energy is usually absorbed or given out in a physical changeA lot of heat or light energy is absorbed or given out in a chemical change.
5)The mass of a substance does not alter in a physical changeThe mass of a substance does alter in a chemical change.
Print Friendly, PDF & Email

Leave a Reply

Your email address will not be published. Required fields are marked *