Calculate the number of α and β particles in the following change: U23592 → 20782Pb

As the mass reduced from 235 to 207, there must be 7 alpha particles liberation as the mass reduces by 28. There must also be 4 beta particles as the atomic number reduces only by 10 not by 14.
U23592 → 20782Pb + 7[42α] + 4[0-1β].
Hence, option D is correct.