The radius of a nucleus with nucleon number 16 is 3 × 10–15 m. Then, the radius of a nucleus with nucleon number 128 will be :- 3 × 10–15 m6 × 10–15 m9 × 10–15 m24 × 10–15 m

The radius of a nucleus (R) is proportional to the cube root of its nucleon number (A). This relationship is expressed by the formula:

R = R₀ * A^(1/3)

where R₀ is a constant.

Given that the radius of a nucleus with nucleon number 16 is 3 × 10–15 m, we can find the value of R₀ as follows:

3 × 10–15 m = R₀ * 16^(1/3) R₀ = 3 × 10–15 m / 16^(1/3)

Now, we can use this value of R₀ to find the radius of a nucleus with nucleon number 128:

R = R₀ * 128^(1/3) R = (3 × 10–15 m / 16^(1/3)) * 128^(1/3)

After calculating the above expression, we find that R is approximately 6 × 10–15 m. Therefore, the radius of a nucleus with nucleon number 128 is 6 × 10–15 m.