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Question
When a beam of sunlight enters a room through a window, we can see tiny particles X suspended in a gas (or rather a mixture of gases) Y which are moving rapidly in a very haphazard manner.
- What could particles X be ?
- Name the gas (or mixture of gases) Y.
- What is the phenomenon exhibited by particles X known as ?
- What is causing the movement of particles X ?
- What conclusion does the existence of this phenomenon give us about the nature of matter ?
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Solution
- The particles, 'X' are dust particles.
- Gas 'Y' is Air.
- This phenomenon being exhibited by 'X' particles is called the Brownian motion.
- The fast moving air molecules are constantly hitting the tiny dust particles, causing them to move rapidly in a very haphazard manner.
- The gaseous matter ‘air’ is made up of tiny particles that are constantly moving.
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