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प्रश्न
In a beam of sunlight entering a room, we can sometimes see dust particles moving in a haphazard way in the air. Why do these dust particles move?
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उत्तर
When a beam of sunlight enters a room, suspended dust particles are seen moving haphazardly. This is because the dust particles are constantly hit by the fast moving particles of air and due to this remain suspended despite gravity acting on them. This is an example of Brownian motion.
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संबंधित प्रश्न
Select the correct alternative
The molecules can move freely anywhere in
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- liquids
- solids
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Write true or false for each statement. Rewrite the false statement correctly.
Matter cannot exist in different states.
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State two characteristics of matter demonstrated by Brownian motion.
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Name one solid, one liquid and one gaseous non-metal.
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- pure substances contain only one kind of particles
- pure substances may be compounds or mixtures
- pure substances have the same composition throughout
- pure substances can be exemplified by all elements other than nickel
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