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States of Matter — Chemistry STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 ScienceChemistryStates of Matter2 Marks
Question
Why is air denser at lower level than at higher altitudes?
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Answer

Heavier air comes down and lighter air goes up. Air at lower level on the surface of earth is denser since it is compressed by mass of air above it, that is why it is denser.

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