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प्रश्न
Assertion: Burning of wood log to charcoal is a physical change.
Reason: The products formed of burning a piece of wood can be easily converted back to wood log.
विकल्प
Both A and R are true and R is the correct explanation of A.
Both A and R are true but R is not the correct explanation of A.
A is true but R is false.
A is false but R is true.
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उत्तर
Both A and R are true but R is not the correct explanation of A.
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संबंधित प्रश्न
Choose the most appropriate answer.
Rising and setting of the sun at a given place is a
Tick the most appropriate answer.
5. Photosynthesis requires
- heat energy.
- wind energy
- sunlight.
- sound energy
Make a list of different types of changes with example.
State whether the following is physical or chemical changes.
shaping a piece of glass —
Fill in the blank
Heat is ________ by a gas during the process of condensation.
Which of the following are physical changes and which are chemical changes ?
Freezing of water
Potassium chloride is added to water and stirred. A salt solution is obtained, which is then boiled, leaving behind a residue.
- Is the above change physical or chemical?
- Name the residue which remains behind after the salt solution is boiled.
- Is the change reversible or not reversible?
- Are the composition and properties of the original substance altered?
- Give a reason why the above experimentation would not be possible if calcium carbonate was taken in place of potassium chloride.
Select the chemical changes from the following list of changes
Rotting of eggs.
Select the chemical changes from the following list of changes
Drying of a fruit
Match the examples of changes in List I with the correct type of change in List II.
| List I | List II |
| 1. Burning of paper | A: Physical change |
| 2. The ringing of an electric bell | B: Chemical change |
| 3. Curdling of milk | |
| 4. Electric light is switched on | |
| 5. Melting of butter |
