NEET2019PhysicsNuclear PhysicsActual
Ba-122 has half life of 2 min. Experiment has to be done using Ba-122 and it takes 10 min to set up the experiment. If initially 80 g of Ba-122 was taken, how much Ba was left when experiment was started?
Options
- A2.5 g
- B5 g
- C10 g
- D20 g
Correct answer
A. 2.5 g
Step-by-step solution
As T _ 1 2 =2 ~min 10 ~min =5 half-lives We know, N N ₀ = ( 1 2 )^ n where, N = remaining of nuclei N ₀= initial number of nuclei n = number of half lives N = N ₀ 2^n = 80 2^5 = 80 32 =2.5 ~g