If 92U235 assumed to decay only by emitting two α- and one β-particles, the possible product of decay is

92U235⟶ZXA+22He4+−1e0Equating mass number of both sides235 = A + 2 × 4 + 0∴A = 235 - 8 = 227Similarly, equating atomic number of both sides92=Z+2×2−1∴Z=92−3=89∴ ZA=89Ac227