Assertion : Earth has an atmosphere but the moon does not. Reason… - Vidyadip

Question

Assertion : Earth has an atmosphere but the moon does not.
Reason : Moon is very small in comparison to earth.

✓

Answer

(b) If root mean square velocity of the gas molecules is less than escape velocity from that planet (or satellite) then atmosphere will remain attached with that planet and if $v_{r m s}>v_{\text {escape }}$ then there will be no atmosphere on the planet. This is the reason for no atmosphere at moon.

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