If an alpha particle (two protons and twoneutrons) is given an initial (nonrelativistic) velocityvat a very far distance and is aimed directly at a gold nucleus(Z=79), what is the closest distance d the alpha particle will come to the nucleus? In this problem you can estimate that the mass of the proton m_p is equal to the mass of the neutron and only consider theeffects of a single gold nucleus. Assume that the alpha particle comes close enough so that the nucleus is not substantiallyscreened by inner-shell electrons.
Express your answer in terms ofm_p, the permittivity of free space epsilon_0, the magnitude of the electron charge e, and v.

Ithink your answer is d

An  atom  (ours, not carroll's) consists of a positively charged  nucleus, surrounded by one or more negatively charged particles called  electrons. the positive charges equal the negative charges, so the atom has no overall charge; it is electrically neutral. most of an atom's mass is in its nucleus; the mass of an electron is only 1/1836 the mass of the lightest nucleus, that of hydrogen. although the nucleus is heavy, it is quite small compared with the overall size of an atom. the radius of a typical atom is around 0.1 to 0.25 nanometres (nm), whereas the radius of a nucleus is about 10-6  nm.  *  if an atom were enlarged to the size of the earth, its nucleus would be only 200 feet in diameter and could easily rest inside a small football stadium.read more on -