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प्रश्न
A physical change is temporary. Explain.
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उत्तर
A physical change is defined as a change in which no new substance is formed.
A physical change is temporary because this change can be easily reversed by reversing the conditions. For example when ice is melted, it gets converted into water by absorbing heat. Water so formed can be easily converted to ice by cooling thus heat is released. Thus physical change is temporary.
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संबंधित प्रश्न
State whether the following statement is true or false. In case a statement is false, write the corrected statement.
Cutting a log of wood into pieces is a chemical change.
Tick (√) the correct alternative from the choice given for the following statement.
An example of both physical and chemical change is
True or false
Dissolving of a solid in liquid is a physical change.
Which of the following are chemical changes ?
- decaying of wood
- burning of wood
- sawing of wood
- hammering of nail into wood
Classify the following as a physical or a chemical change.
Butter getting rancid
Given reason:
Freezing of water to ice and evaporation of water are physical changes.
Change is the law of nature and occurs in our everyday life, at all times and in all places.
Differentiate between the following change with a suitable example.
Slow and fast change.
When a woolen yarn is knitted to get a sweater, the change can be classified as ____________.
Match the following
| Sr. No. | A | B | C |
| 1. | Melting | Change of state from liquid to solid | Ticking of clock |
| 2. | Condensation | Change of state from liquid to gas | Formation of ice cube |
| 3. | Evaporation | Change of state from solid to liquid | Collecting flowers |
| 4. | Freezing | Change of state from gas to liquid | Ice cube to water |
| 5. | Periodic change | Occurs at irregular time intervals | Water to steam |
| 6. | Non-periodic change | Occurs at regular time intervals | Steam to water drops |
Cutting a log of wood into pieces is a chemical change.
