(a) Use an excel spreadsheet with the data provided

activity time (sec)
4022   38.6
3424   77.0
2613   113.8
2158   152.6
1590   188.9
1337   228.6
940     269.7

Prepare a graph of activity vs. seconds. Use a trend line to produce the best exponential line through the points.

(b) Use the excel spreadsheet again with the data to prepare a graph of ln(activity) vs. time (seconds) . Use lin fit to produce the best straight line through the graph through the points and have the equation of that line printed on the graph.

ln (activity)_t= _________t+_____________

(c) Use the y-intercept of the line to calculate the activity which was present at the original time t=0

(d) Use the slope of the line to determine the value of the rate of constant or decay constant

K=____________(sec)_______

(e) Use the equation to calculate the time at which the activity has decreased to 50.