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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.
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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
Classify the following as chemical or physical change:
Burning of paper and wood
Explain the following giving an example.
Pure substance
Changes in which only ______ properties of a substance change are called physical changes.
Tick the most appropriate answer.
4. Chemical changes involve
- change in shape.
- change in size.
- change in molecular composition.
- none of these
Tick (√) the correct alternative from the choice given for the following statement.
An example of both physical and chemical change is
Make a list of different types of changes with example.
What is a physical change ? Give two examples of physical changes.
Name the following:
The final product of the physical change involved during the ‘melting of a piece of wax’.
Give the reason why the following is considered as chemical changes.
A piece of magnesium strip is dropped into a beaker containing dilute hydrochloric acid.
Digestion of food is a physical change.
