Part of Lesson Plan: Why is Water Sticky? -- Jill Sperling

Activity Overview / Details

For this activity, take the class outside to a large, grassy area (I usually use our school's football field). You don't want to do this activity on concrete or dirt because it greatly increases the risk of a student getting hurt!  

Once outside, tell the class that they were so well behaved during the notes that they get a special treat.  Ask them to raise their hands if they ever played "Red Rover, Red Rover" in elementary school. (Most students will have some experience with this game.)  Divide the class into two teams of equal size (try to mix males & females during the sorting process).  Have each team member hold hands with one another and spread themselves out so that their arms are out and there is some tension between them.  

CAUTION:  Make sure that the students are only holding hands, not wrists!  When they join at the wrists, the connection is a lot stronger (students who have played before will realize that and try to get an advantage over the other team).  However, there is a big difference between playing this in elementary school and playing as a teenager.  It is MUCH EASIER to get hurt if they are holding at the wrists!

The teams should line up so that they are facing each other.  Make sure that there is a fair amount of distance between the two groups.  

Each team should designate one person to serve as the "caller".  This person will be responsible for calling the name of a student from the other team when the time comes. Once each team has a "caller", one team starts the game by singing the words "Red Rover, Red Rover send ____________ on over."  (the caller would insert the name of a student)  At that point, the student that was selected will leave their team and run towards the other team.  The object is for them to try to break through the line of students.  If they break through, the student returns to their home team.  If they get caught, they have to stay on that team. 

This continues back and forth in the same fashion.  The team that has the most members at the end of the game WINS!!  (you can adjust the time as needed but let them play for at least 10-15 minutes otherwise they won't have enough background information to draw conclusions from).  

After the game is over, have students either form a circle and sit down on the grass (or return to the classroom if the grass is wet or the weather is bad).  Ask the class what the purpose of playing Red Rover, Red Rover was.  (They will mostly say that you are a cool teacher who gave them a break from learning.)  Have them review the concepts that were taught in class earlier in the period (hydrogen bonds and surface tension).  Ask them how the game helps to demonstrate those principles. What did they individually represent?  Why were they joined at the hands?  What determined if someone running towards the team would break through or get caught?

Guide students to the following conclusions:

• Each individual student in the line represented a WATER MOLECULE.
• The joined hands between two "water molecules" represented a HYDROGEN BOND.
• The entire line (team) represented SURFACE TENSION of water.
• If the person (object) had enough force & weight, it would break through the surface tension.  If not, they would get caught.