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Question
Give reasons for the following observation:
The smell of hot sizzling food reaches you several metres away, but to get the smell from cold food you have to go close.
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Solution
- Solids diffuse at a very slow rate. However, if the solid's temperature is increased, the rate of diffusion of the solid particles into the air increases.
- This is due to an increase in the kinetic energy of solid particles. Hence, the smell of hot, sizzling food reaches us even at a distance, but to get the smell of cold food, we have to go close.
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