Question

Which of the following quantities for a nucleus is independent of its mass number?

• A. Density
• B. Volume
• C. Mass
• D. Radius

Answer 1

Answer: (A)

Nuclear radius $R=R_0{A}^{1/3}$
Nuclear volume $V=\frac{4}{3}\pi R^3=\frac{4}{3}\pi R_0^{3}A$
Nuclear density $\rho =\frac{mA}{\frac{4}{3}\pi {\left(R_0{A}^{1/3}\right)}^3}$
$\rho =\frac{m}{\frac{4}{3}\pi R_0}$
where $A$ is the mass number. We can see that density is independent of mass number.