Question

It the radius of a nucleus of mass number 3 is R. then the radius of a nucleus of mass number 81 is 

(A) 27 R 

(B) 9 R 

(C) 3 R 

(D) (27)^(1/2)R

Answer 1

The correct option is (C) 3 R.

Explanation:

R = R_o(A)^(1/3)

A is mass number i.e. R ∝ A^(1/3)

 Hence (R / R') = [(3)^(1/3) / (81)^(1/3)] = (3 / 81)^(1/3) = (1/3)

∴  R' = 3R