The mass number of a nucleus whose radius R is 2.4 fm, will be equal to:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 8
The radius of a nucleus depends on its mass number as
\( \displaystyle R = R_0\,A^{1/3} \)
with \( R_0 = 1.2\,\mathrm{fm} \) (the standard value, as the question does not give it).
\( \displaystyle A^{1/3} = \frac{R}{R_0} = \frac{2.4}{1.2} = 2 \)
\( \displaystyle A = 2^{3} = 8 \)