Question 1195554
.
Bismuth-210 is an isotope that radioactively decays by about 13% each day, 
meaning 13% of the remaining Bismuth-210 transforms into another atom 
(polonium-210 in this case) each day. If you begin with 133 mg of Bismuth-210, 
how much remains after 6 days?
After 6 days,
mg of Bismouth-210 remains.
~~~~~~~~~~~~~~~~


<pre>
The remaining mass of Bismuth-210 after one day is

    M(1) = {{{M(0)*(1-0.13)}}} = {{{0.87*M(0)}}},


where M(0) is the starting amount of Bismuth-210.


After 2 days the remainig mass is  {{{0.87^2*M(0)}}}.

After 3 days the remainig mass is  {{{0.87^3*M(0)}}}.


   . . . and so on . . . 


After n days the remainig mass is  M(n) = {{{0.87^n*M(0)}}}.


Concretely for this problem, the remaining mass after 6 days will be

    M(6) = {{{0.87^6*133}}} =  57.672 mg  (rounded).    <U>ANSWER</U>
</pre>

Solved.


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On radioactive decay, &nbsp;see the lesson

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/logarithm/Radioactive-decay-problems.lesson>Radioactive decay problems</A> 

in this site.


You will find many similar &nbsp;(and different) &nbsp;solved problems there.



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Also, &nbsp;you have this free of charge online textbook in &nbsp;ALGEBRA-I &nbsp;in this site

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson>ALGEBRA-I - YOUR ONLINE TEXTBOOK</A>.


The referred lesson is the part of this online textbook under the topic "<U>Logarithms</U>".



Save the link to this online textbook together with its description


Free of charge online textbook in ALGEBRA-I
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