Question 1149888
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A) Since p = f(t) is the percentage that remains after t hours, the initial value is 100.  Then that percentage is multiplied by 1/2 each hour.  So<br>
ANSWER: {{{f(t) = 100*(.5)^t}}}<br>
B) The p-intercept is f(0) = 100.  It states the obvious fact that in the beginning 100% of the element remains.<br>
C) {{{f(9) = 100*(.5)^9 = 100/2^9 = 100/512}}} which is approximately 1/5 or 0.2.  It means after 9 hours only about 0.2% of the element remains.<br>
D) From the statement of the problem, the half-life is 1 hour.<br>