MHT CET202522 Apr 2025Evening ShiftPhysicsNuclear PhysicsActual
A radioactive element A decays into radioactive element C by the following processes in succession. A ~B + ₂ H _ e ^4 ; B C +2 e ⁻ Then elements
Options
- AA and B are isobars.
- BA and C are isobars.
- CA and C are isotopes.
- DA and B are isotopes.
Correct answer
C. A and C are isotopes.
Step-by-step solution
Analyzing the radioactive decay chain of element A = _Z^M A : Alpha decay: A B + ₂^4 He By conservation: mass number M = M_B + 4 M_B = M - 4 Atomic number Z = Z_B + 2 Z_B = Z - 2 Thus B = _ Z-2 ^ M-4 B Beta decay (2 ^- ): B C + 2 _ -1 ^0 e Mass number: M - 4 = M_C Atomic number: Z - 2 = Z_C - 2 Z_C = Z Thus C = _Z^ M-4 C A and C share atomic number Z but differ in mass number ( M vs. M-4 ), confirming they are isotopes.