Question

In our daily life we observe a lot of changes around us some of them are good for us and

some are not. These changes can be categorized into two categories ie Chemical changes

and Physical changes.

Answer 1

ya...it is true statement......

and...

physical changes are those in which new substances are not formed....

but in chemical changes new substances are formed.....

hope it helps dude.....

by..

roshan.....

be....

brainly...###

Answer 2

Changes Around Us

1. Many changes are taking place around us on their own.

2. We can bring about a change in a substance by doing one or more of the following.
 Heating. Applying forceMixing it with something else. 
3. Changes caused by heating: When an object is heated, it gets affected in one or many possible ways.Some objects get hot but do not change in any other way.Some objects get hot and also expand in size.Some objects get hot and begin to burn.Some objects get hot and change their state. 
4. Changes by applying pressure : When we apply force to an object,
We can change its shape and size.Air can be compressed.Metals can be hammered into thin sheets.Elastic can be stretched.Cotton can be spun into thin threads. 
5. Changes by mixing a substance with other: We can bring about a change in a substance by mixing it with another, e.g.,Making solution by mixing water soluble substances in water.
 
6. Expansion: Metals expand on heating and contract on cooling.

7. Chemical changes:These are the changes in which chemical properties of a substance changes, and a new substance is formed. For example: cooking of food. 

8. Physical changes:These are the changes in which only physical property of a substance changes and no new substance is formed.
 
9. Characteristic of physical changes :
No new substances are formed.Products are identical to the reactant.These changes are reversible. 10. Characteristics of chemical changes :Properties of products are different from the properties of reactants.Most of the chemical changes are irreversible.These changes always result in energy changes. 
11. Reversible changes: These are the changes that can be reversed. For example stretching of rubber.

 12. Irreversible changes:These are the changes which cannot be brought back to its stretching of rubber.

 13. Contraction: A process in which an object becomes smaller is called contraction.

 14. Evaporation: A process in which liquid changes into vapor on heating is called evaporation.

 15. Melting: A process in which solid changes into liquid on heating is called melting or fusion.

 16. Melting point: A constant temperature at which solid starts melting. This temperature is called the melting point of that solid.

 17. Freezing: A process in which liquid changes into solid is called freezing.

 18. Force: A push or pull acting on a body which tends to change its state of rest or motion is called a force.