Question

For a radioactive material, half-life is 10minutes. If initially there are 600 number ofnuclei, the time taken (in minutes) for thedisintegration of 450 nuclei is
(1) 30 (2) 10
(3) 20 (4) 15

Answer 1

Answer:

Correct option is

B

20

Half life =10min=

λ

ln2

Nuclei disintegrate = 450

Nuclei left = 600-450 =150

N=N

o

e

−λ

t

150=600e

10

−ln2

t

so, t = 20 minutes