Students predict the spread of disease to be exponential. They then do a hands on "sharing of bodily fluids" and see the actual data and compare these results to the projected model. You actually see the number of infected after each sharing to see the shift of the model easier. Written to be completed with probes or without, depending upon classroom activities.

Make copies of the activity. Run off extra data sheets as needed, this depends upon the method you use. Obtain as many cups as you have students and number them. Place water in all cups except one, which you know the number of. In the one contaminated cup place the 1 M sodium hydroxide solution. Obtain pipettes for each student.

Have students follow the experiment procedures in the student lab.