Q$.1$ If you know that the atomic number of an element is $(31)$ and the radius of its nucleus is $(4\mathrm{.}8{10}^{-15})m,$ then the number of neutrons in its nucleus is: $\{$Knowing that the radius of the nucleus is $\{$:$(1\mathrm{.}2{10}^{-15})m\}?$

Q$.2$ Calculate the energy equivalent to a mass of $8$ g of the substance in million electron volts?

Q$.3$ If the mass of the deuterium nucleus $(12H)$ is $2\mathrm{.}014$ u $,$ calculate the difference between it and the mass of its components in atomic mass units, which is: $($ M protons $=1\mathrm{.}007u$ neutrons $=1\mathrm{.}009u$

Q$.4$ In the decay, identify the mass number and the atomic number of the Ra nucleus?

Q$.5$ Consider the ${?}_{29}^{65}Cu$ nucleus. Find approximate values for its $($a$)$ radius, $($b$)$ volume, and $($c$)$ density.