half life

Asked by  | 21st Feb, 2010, 07:57: PM

Expert Answer:

It is given that disintegration rate to be proportional to the number of radioactive atoms in the sample.

So, [A]o = 4280 counts per min

[A] = 1070 counts per min

time is from 1:35 min to 4:55 min

So, 200 minutes

k = (2.303/t) log ( [A]o/ [A] )

k = (2.303/200) log(4280/1070)

 = 0.127

t1/2 = 0.693/k = 0.693/ 0.127 = 5.45 min

Answered by  | 24th Feb, 2010, 04:22: PM

Queries asked on Sunday & after 7pm from Monday to Saturday will be answered after 12pm the next working day.