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प्रश्न
Name a chemical change which takes place in presence of:
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उत्तर
Heat:
- Burning of paper.
- Cooking of food need heat.
Light :
- Formation of food by plants i.e. photosynthesis need light.
- Hydrogen and chlorine react in presence of light
Electricity:
- Water breaks into hydrogen and oxygen on passing electricity.
- Sodium chloride solution breaks up into its components sodium and Chlorine on passing electric current through sodium chloride solution.
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संबंधित प्रश्न
Choose the most appropriate answer.
Rising and setting of the sun at a given place is a
Solve this crossword by using the clues that follow.

Across
1. Energy in the form of sunlight is absorbed by the green plants in this process.
4. The reddish-brown substance formed over iron in the presence of oxygen and moisture.
5. This change is permanent and irreversible.
6. The process in which a solid directly changes into gaseous state.
Down
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2. Occurrence of this is a non-periodic change as well as a natural change.
3. It is a physical change
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Natural changes which take place in nature on their own, are beyond the control of human being.
