When radium-226 decays radioactively, it emits an alpha particle (the nucleus ofhelium), and the end product is radon-222. We can model thisdecay by thinking of the radium-226 as consisting of an alpha particle emitted from the surface of the spherically symmetric radon-222 nucleus, and we can treat the alpha particle as a point charge.The energy of the alpha particle has been measured in the laboratoryand has been found to be 4.79 MeV when the alpha particle isessentially infinitely far from the nucleus. Since radon is muchheavier than the alpha particle, we can assume that there is no appreciable recoil of the radon after the decay. The radon nucleuscontains 86 protons, while the alpha particle has 2 protons and theradium nucleus has 88 protons. (a) What was the electric potentialenergy of the alpha-radon combination just before the decay, inMeV and in joules? (b) Use your result from part (a) to calculatethe radius of the radon nucleus.