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Give reason for the following observatio...

Give reason for the following observations.
(a) Naphthalene balls disappear with time without leaving any solid.
(b) We can get the smell of perfume sitting several metres away.

Text Solution

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(a) Naphthalene balls disappear with time without leaving any solid because of they undergoes sublimation easily i.e., the change of state of naphthalene from solid to gas takes place easily
(b) Perfumes have high degree of vaporisation and its vapour diffuses into the air easily. Therefore we can get the smell of perfume sitting several metres away.
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NCERT ENGLISH-MATTER IN OUR SURROUNDINGS-Exercise
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  2. Liquids generally have lower density as compared to solids but you mus...

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  3. Convert the following temperatures to the celsius scale. (a) 300k (...

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  4. What is the physical state of water at: a. 250^(@)C b. 100^(@)C?

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  5. For any substance, why does the temperature remains constant during th...

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  6. Suggest a method to liquefy atmospheric gases.

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  7. Why does a desert cooler cool better on a hot dry day?

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  8. How does the water kept in an earthen pot (mataka) become cool during ...

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  9. Why does our palm feel cold when we put some acetone or petrol or per...

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  10. Why are we able to sip hot tea or milk faster from a saucer rather tha...

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  11. What type of clothes should we wear in summer?

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  12. Convert the following temperatures to the celsius scale. (a) 293k (...

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  13. Convert the folowing temperature to the kelvin scale. (a) 25^(@)C (b...

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  14. Give reason for the following observations. (a) Naphthalene balls d...

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  15. Arrange the following substances in increasing order of forces of attr...

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  16. What is the physical state of water at- (a) 25^(@) (b) 0^(@)C (c) 1...

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  17. Give two reasons to justify- (a) Water at room temperaure is a liqui...

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  18. Why is ice at 273k more effective in cooling than water at the same te...

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  19. What produces more severe burns, boiling water or steam?

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