Question
Question: Number of nuclei of a radioactive substance at time t = 0 are 1000 and 900 at time t = 2 s. Then num...
Number of nuclei of a radioactive substance at time t = 0 are 1000 and 900 at time t = 2 s. Then number of nuclei at time t = 4 s will be:
A
800
B
810
C
790
D
700
Answer
810
Explanation
Solution
In 2s only 90% nuclei are left behind. Thus, in next 2s 90% of 900 or 810 nuclei will be left.