CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon


Question

The half life of a radioactive substance is 30 minutes. The time taken between 40% decay and 85% decay of the same radioactive substance in minutes is:
  1. 15
  2. 60
  3. 30
  4. 45


Solution

The correct option is B 60
t1/2=30 min
N1=N0(12)T130N2=N0(12)T230
N1=10040=60
N1 = Atom remains undecay
N2 = 100-85
N2 = Atom remains undecay
60=N0(12)T130               (1)
15=N0(12)T130              (2)
By (1) and (2)
4=(12)T1T230
4=2(T1t2)30
(2)2=(2)30T1T2
2=T1T230
T2T1=60 min

flag
 Suggest corrections
thumbs-up
 
0 Upvotes


Similar questions
View More


People also searched for
View More



footer-image