There is relatively little empty space between atoms in solids and liquids, so that the average density of an atom is about the same as matter on a macroscopic scale-approximately 10³ kg/m³. The nucleus of an atom has a radius about 10^-5 that of the atom and contains nearly all the mass of the entire atom.

(a) What is the approximate density of a nucleus?

(b) One remnant of a supernova, called a neutron star, can have the density of a nucleus. What would be the radius of a neutron star with a mass 10 times that of our Sun (the radius of the Sun is 7 x 10⁸ m)?