MHT CET202120 Sep 2021Morning ShiftPhysicsNuclear PhysicsActual
A sample of radioactive element contains 8 10¹⁶ active nuclei. The halt-life of the element is 15 days. The number of nuclei decayed after 60 days is
Options
- A7.5 10⁺¹⁶
- B2.0 10¹⁶
- C0.5 10¹⁶
- D4.0 10¹⁶
Correct answer
A. 7.5 10⁺¹⁶
Step-by-step solution
Half life, T =15 days, time t =60 days =4 ~T The number of nuclei remaining is given by aligned & N = N ₀ ( 1 2 )^ n = N ₀ ( 1 2 )^4= 1 16 8 10¹⁶ & =0.5 10¹⁶ & No. of nuclei decayed = N ₀- N & =8 10¹⁶-0.5 10¹⁶=7.5 10¹⁶ aligned