Editing Disease Transfer (section)

== Demonstration ==

;Preparation:
* Fill the dixie cups about 1/3 with water. Select a tenth of the cups (rounded up) and add 5mL of the NaOH solution to them. To do so, first pour the NaOH into the beaker, then measure 5mL using the graduated cylinder. Be sure to select the cups at random!
;Presentation:
# Have students all pick a cup of water, and make sure to remind them that they should NOT drink from them. Some of these cups are contaminated with a mysterious disease! Be sure to state how many of the cups are contaminated.
# Explain that students will be mixing their water cups with the others around them. Each student will end up mixing four times, and shouldn't mix more than once with the same person. To mix waters, one of the students should pour their cup fully into the other student's cup. Then, that student should pour water back into the first student's cup until they are equal.
#* Ask the students to all choose one person next to them, shake hands, and mix their water with them. 
#* Have students now choose someone they have to walk to, shake hands, and mix their water again.
#* Have students now choose someone nearby that they haven't mixed water with, shake hands, and mix their water again.
#* Have students choose someone they know that they haven't mixed water with, shake hands, and mix their water again.
# After students have finished, have them all sit in their seats or in a row. Let them know that you are now going to check who caught the mysterious illness by using your indicator. Walk along and put 3-4 drops of the indicator in each cup, and have students gently swirl their cups to see if a color change happens.
# After noting how many students have a color change, remind them of how few of them were originally infected. How did it spread so quickly?