The mass number of helium is 4 and that of sulphur is 32. How many times the radius of sulphur nucleus is bigger than that of helium?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 2
The nuclear radius depends on the mass number as \( R = R_0A^{1/3} \), where \( R_0 \) is a constant (about \( 1.2\times10^{-15}\,\mathrm{m} \)). The nuclear density is the same for all nuclei.
\( \displaystyle \frac{R_S}{R_{He}} = \left(\frac{A_S}{A_{He}}\right)^{1/3} = \left(\frac{32}{4}\right)^{1/3} = 8^{1/3} = 2 \)