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प्रश्न
Ice kept in a beaker, slowly melts and turns into water. The water in the beaker on solidification is freezing turns back to ice. Give four reasons why the change from ice to water and water back to ice is considered a physical change.
उत्तर
Both changes are physical changes since
- The change is – temporary
- It is a reversible change
(heating and cooling reverse the change)
heating of ice – turns it into the water,
cooling of water – turns it back into ice - No new products are formed since both ice and water are chemical – ‘H20’
- Properties of the original substance are not altered.
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संबंधित प्रश्न
Tick the most appropriate answer.
3. Physical changes are
- permanent.
- periodic,
- temporary
- irreversible.
Fill in the blank
change in which the substance can be brought back to its original state is called a ............... change.
Fill in the blank.
Heat is .................... by a gas during the process of condensation.
Write short answer.
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X and Y cannot be broken down into simpler substances by simple chemical reactions. Which of the following statements concerning X, Y and P are correct ?
- P is a compound
- X and Y are compounds
- X and Y are elements
- P has a fixed composition
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Physical change and chemical change
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