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प्रश्न
Give the main differences between physical changes and chemical changes.
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उत्तर
Important differences between a physical and a chemical change are given below:
| PHYSIAL CHANGE | CHEMICAL CHANGE |
| 1. No new substance is formed. | 1. A new substance is formed. |
| 2. Physical change is reversible. | 2. Chemical change is usually irreversible. |
| 3. It is a temporary change. | 3. It is a permanent change. |
| 4. No heat energy is evolved or absorbed. | 4. Heat energy is evolved or consumed in a large amount. |
| 5. Examples: Melting of ice, formation of clouds, tearing of cloth etc. | 5. Examples: Rusting of iron, ripening of fruits, cooking of food etc. |
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संबंधित प्रश्न
What will you take into account while identifying the following?
A physical change in a substance.
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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Change of seasons is a periodic change while the change of weather is a non-periodic change.
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Select the correct answer from the choice given below to complete the sentence
A change in which a substance retains its identity is a
______ change.
Name the following.
The product of the chemical change in keeping a polished iron nail exposed to the atmosphere.
Which of the following is a physical change?
Match the items of Column I with the items of Column II.
| Column I | Column II | ||
| (a) | Large crystals | (i) | Turns lime water into milky |
| (b) | Depositing a layer of zinc on iron | (ii) | Physical change |
| (c) | Souring of milk | (iii) | Rust |
| (d) | Carbon dioxide | (iv) | Sugar candy (Mishri) |
| (e) | Iron oxide | (v) | Chemical change |
| (f) | Dissolving common salt in water | (vi) | Galvanisation |
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