226 88 86 Suppose a Ra nucleus at rest and in ground state undergoes a-decay to a 222 Rn nucleus in its excited state. The kinetic energy of the emitted a particle is found to be 4.44 MeV. 2 Rn nucleus then goes to its ground state by y-decay. The energy of the emitted y photon is 222 86 ke V. 222 86 Rn 222.000 u, atomic mass of a particle 88 [Given: atomic mass of Ra = 226.005 u, atomic mass of = 4.000 u, 1 u = 931 MeV/c, c is speed of the light]