NEET Physics Nuclei Questions Solved


A radioactive element emits 200 particles per second. After three hours 25 particles per second are emitted. The half life period of element will be
(a) 50 minutes            (b) 60 minutes
(c) 70 minutes            (d) 80 minutes

(b) R=dNdtNR2R1=N2N1

But N2N1=12t1/225200=18=123tt1/2=3

 t1/2=t3=33=1 hour = 60 minutes

Difficulty Level:

  • 6%
  • 65%
  • 24%
  • 6%
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