Assertion A : Earth has atmosphere whereas moon doesn’t have any atmosphere.

Question

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R. 

Assertion A : Earth has atmosphere whereas moon doesn’t have any atmosphere. 

Reason R : The escape velocity on moon is very small as compared to that on earth. 

In the light of the above statement, choose the correct answer from the options given below : 

(1) A is true but R is false 

(2) A is false but R is true 

(3) Both A and R are correct but R is NOT the correct explanation of A 

(4) Both A and R are correct and R is correct explanation of A

Answer 1

(4) Both A and R are correct and R is correct explanation of A

At Moon, due to low escape velocity, the rms velocity of molecules is greater than escape velocity. Hence molecules escape and there is no atmosphere at Moon.