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Question
Differentiate between a physical change and a chemical change with reference to – Energy change taking place during the respective change.
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Solution
| Physical change | Chemical change |
| Generally, energy is neither absorbed nor released during the change. | Generally, energy is either absorbed or evolved during change. |
| Example: Melting of ice, melting of the wax. | Example: Change of milk into curd and burning of a candle. |
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| 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 |
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A rough piece of wood is sanded and polished resulting in change in texture, Rusting of a iron nail, Painting the grill, Bending a paper clip, Pounding silver into thin plate, Rolling the chappathi dough into thin wire, Occurrence of day and night, eruption of volcano, burning of matchstick, dosa from the batter, blinking of eyelids, occurrence of a thunderstorm, rotation of the earth, formation of eclipses.
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| 1. | ||
| 2. |
Assertion: The explosion of fire cracker is a physical change.
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