Physical and Chemical Changes: It is not necessary that reactions can be carried only in the science laboratory. A large number of reactions keep occurring in our daily life. Everything is changing around us. Reactions are continuously taking place in our environment. Yes, every moment. Do you know that there are two kinds of reactions first one is called physical reactions and the other is called chemical reactions?
What is a Physical Change – Definition
A Physical change is a temporary change in which the composition of the matter remains unaltered. It means their internal structure remains unchanged.
- No new substance is formed.
- The change is temporary and reversible.
- There is no change in mass. (example – sugar or water)
- No heat is absorbed and given out during this process.
What is a Chemical Change – Definition
A chemical change is a permanent change in which an entirely new substance is formed with different properties.
- One or more entirely new substance is formed.
- The change is permanent.
- The change may be reversible or irreversible.
- Change in the composition and properties of the substance takes place.
- Heat or light may be given out or absorbed.
Examples of Physical and Chemical Changes
So, paper remains paper and water remains water. There is no change in properties of substances. These are called physical changes of physical reactions.
In physical reaction shape or phase can change but new substances are not produced.
Look at these three different reactions –
|Burning of a matchstick||Rusting of iron||Bursting of firecrackers|
Can you tell what is common in these three reactions?
Matchstick, cracker, and nails are no longer the same. A new substance is formed. They have changed. These are known as chemical reactions.
In these kinds of reactions, changes happen at the molecular level. Always a new substance is formed.
Physical Change Examples
A physical change is a temporary change. There may be some changes in physical properties such as state, color, smell etc.
- Dissolving of sugar in water.
- Switching off an electric heater.
- Magnetizing a needle.
- Melting of an ice cube.
- Tearing Paper.
- Changing shapes of Clay.
- Cutting a pile of wood.
Dissolution, precipitation, evaporation, condensation freezing, melting, and sublimation are some of the other examples.
Chemical Change Examples
A Chemical Change is a permanent change.
- Formation of curd.
- Growing of seedlings from the seed.
- Burning of fuels.
- Digestion of Food.
- Rusting of Iron.
- Burning of Matchstick.
- Bursting of firecrackers.
- Getting Old.
- Frying egg.
Difference Between Physical And Chemical Change
|Physical Change||Chemical Change|
|Physical changes only affect physical properties.||Chemical changes will affect both physical and chemical properties.|
|Physical changes produce no energy.||Chemical changes produce energy generally in the form of heat, light, or sound.|
|Physical changes produce no new substances the atoms are arranged the same way in the products and reactants.||Chemical changes produce new substances the atoms rearrange and form new compounds.|
|Physical changes are generally easy to reverse.||Chemical changes are not easily reversible without an additional chemical reaction.|
This is all about the basics of Examples, Difference of Physical and Chemical Changes