Extra questions
1.Give examples of the changes where energy is absorbed and where energy is released.
2.Give 5 examples of the changes which are physical and reversible changes.
3.Give 5 examples of the changes which are physical and irreversible changes.
4.Give 5 examples of the changes which are chemical and irreversible changes.
5.Differentiate between reversible and irreversible changes.(O_O)
Answers
Answer:
1. When liquid water becomes ice, energy is released.
2. Melting: Melting is when solid converts into a liquid after heating. Example of melting is turning of ice into water.
Freezing: Freezing is when a liquid converts into a solid. Example of freezing is turning of water into ice.
Boiling: Boiling is when a liquid converts into a gas.
3. Tearing of paper, Increase in height, Increase in weight,Cracking an egg,Chalk getting small after use.
4. Heating, Burning, Mixing, Cooking, Powdering.
5. Reversible change :- 1. A substance can return in it's original state. 2. The chemical properties of the substances don't change.
Irreversible change:- 1. A substance cannot return in it's original state. 2. The chemical properties of the substances change.