The gravitational force between an H-atom and another particle of mass m will be given by Newton’s law: F = G M.m/r2 , where r is in km and (a) M = mproton + m electron (b) M = mproton + melectron – B/c2 (B = 13.6 eV) (c) M is not related to the mass of the hydrogen atom (d) M = mproton + m electron |V |/c2 – (|V | = magnitude of the potential energy of electron in the H-atom)
Correct option is B) During formation of H-atom some mass of nucleons convert into energy by E=mc2, this energy is used to bind the nucleons along with nucleus. So mass of atom becomes slightly less than sum of actual masses of necleons and electrons Actual mass of H atom =Mp+Me=c2BE (c2B is binding energy) B.E(B) of H atom is 13.6eV per atom
