info@clay6.com
logo

Ask Questions, Get Answers

X
 
Answer
Comment
Share
Q)

Half-lives of two radioactive elements A and B are 20 minutes and 40 minutes, respectively.Initially, the samples have equal number of nuclei. After 80 minutes, the ratio of decayed numbers of A and B nuclei will be:

$\begin{array}{1 1}(1) 1:16 \\ (2) 4:1 \\(3) 1:4 \\ (4) 5:4 \end{array} $

1 Answer

Comment
A)
Need homework help? Click here.
Solution :
80 minutes = 4 half-lives of A = 2 half-lives of B
Let the initial number of nuclei in each sample be N
$N_A$ after 80 minutes $= \large\frac{N}{2^4}$
=> Number of A nuclides decayed $=\large\frac{15}{16} $$N$
$N_B$ after 80 minutes $= \large\frac{N}{2^4}$
=> Number of B nuclides decayed $=\large\frac{3}{4} $$N$
Required ratio $= \Large\frac{15/16}{3/4}$
$\qquad= \large\frac{5}{4}$
Home Ask Homework Questions
...