Question 1199030
The half life of a certain isotope is 8.5 hours. If we have a sample of 20 ounces of that isotope, how much of it will remain after one full day?

The correct answer is one of the following.  Which one is correct?

A) 0.28 ounces 

B) 0.14 ounces 

C) 1.41 ounces 

D) 2.82 ounces 
<pre>If {{{1/2}}}-life consists "a" time periods, the DECAY CONSTANT, or {{{matrix(1,3, k, "=", ln(1/2)/a)}}}

                                                So, we have: {{{matrix(1,3, k, "=", ln(1/2)/8.5)}}}                                         
                                                             {{{matrix(1,10, k, "=", - .08155, "=", - .0816, "(ROUNDED", to, 4, decimal, "places)")}}}

                            OONTINUOUS GROWTH/DECAY formula: {{{matrix(1,3, A, "=", A[o]e^(kt))}}}
                                                 So, we get: {{{matrix(1,3, A, "=",20e^(- .0816(24)))}}} --- Substituting {{{system(matrix(2,3, 20, for, A[o], - .0816, for, k), matrix(1,9, and, 24, "(hours", in, 1, full, "day)", for, t)))}}} 

<font color = red><font size = 4><b>Amount remaining after 1 full day</font></font></b> (24 hours): A = 2.82168 = <font color = red><font size = 4><b>2.82 </font></font></b>(ROUNDED to 2 decimal places) ounces<font color = red><font size = 4><b> (CHOICE D)</font></font></b>.</pre>