NEET2022PhysicsNuclear PhysicsActual
At any instant, two elements X₁ and X₂ have same number of radioactive atoms. If the decay constant of X₁ and X₂ are 10 and respectively. Then the time when the ratio of their atoms becomes 1 e respectively will be:
Options
- A1 11
- B1 9
- C1 6
- D1 5
Correct answer
B. 1 9
Step-by-step solution
By radioactivity law, we have, N = N _o e^ - t (where, the symbols have their usual meanings) Hence, for two elements, N ₁ ~N ₂ = N _o e^ -10 t ~N _o e^ - t = 1 e Hence, e^ -9 t =et= 1 9