Discover the answers you need at Westonci.ca, a dynamic Q&A platform where knowledge is shared freely by a community of experts. Connect with professionals ready to provide precise answers to your questions on our comprehensive Q&A platform. Join our Q&A platform to connect with experts dedicated to providing accurate answers to your questions in various fields.

49 After decaying for 48 hours, l/16 of the original mass of a radioisotope sample remains unchanged. What is the half-life of this radioisotope?
(1) 3.0 h (3) 12 h(2) 9.6 h (4) 24 h


Sagot :

1/16 left would imply 4 half lives have passed (1/2 left = 1, 1/4 left = 2, 1/8 left = 3, 1/16 left = 4). So 4 half lives passed in 48 hours, meaning dividing 48 by 4 will give you the length of 1 half life. Which in this case is 12 hours.

Answer:

The half life of the radioisotope is 12 hours.

Explanation:

Initial mass of the radioisotope = x

Final mass of  the radioisotope = [tex]\frac{1}{16}\times x[/tex] = 0.0625x

Half life of the radioisotope =[tex]t_{\frac{1}{2}}[/tex]

Age of the radioisotope = t = 48 hours

Formula used :

[tex]N=N_o\times e^{-\lambda t}\\\\\lambda =\frac{0.693}{t_{\frac{1}{2}}}[/tex]

where,

[tex]N_o[/tex] = initial mass of isotope

N = mass of the parent isotope left after the time, (t)

[tex]t_{\frac{1}{2}}[/tex] = half life of the isotope

[tex]\lambda[/tex] = rate constant

[tex]N=N_o\times e^{-(\frac{0.693}{t_{1/2}})\times t}[/tex]

Now put all the given values in this formula, we get

[tex]0.0625x=x\times e^{-(\frac{0.693}{t_{1/2}})\times 48 h}[/tex]

[tex]\ln(0.0625) \times \frac{1}{(-0.693\times 48 h)}=\frac{1}{t_{1/2}}[/tex]

[tex]t_{1/2} = 11.99 hours = 12 hours[/tex]

The half life of the radioisotope is 12 hours.

We hope our answers were helpful. Return anytime for more information and answers to any other questions you may have. Thanks for stopping by. We strive to provide the best answers for all your questions. See you again soon. Westonci.ca is your trusted source for answers. Visit us again to find more information on diverse topics.