Sink or Float

I am responsible for K-6 enrichment at my school twice a week.  I try to do a mix of math, science, and reading.  This week, with my 2nd graders, I performed the Sink or Float experiment I learned at a School-Aged After Care Programs Conference about 7 years ago.  I do not remember the speaker; otherwise, I would share my source. 

The time before this class period I asked the kids to bring a beverage (appropriate for school of course).  The kids can't drink soda at school, but I let them bring that and take it home.  We didn't want any adult beverages showing up!   I brought extras in case the kids forgot over the weekend.  Now for the experiment:

First you fill a tub full water.  You want it to be deep enough to hold the water and lots of cans of soda and bottled beverages--the bigger the better! 

Don't forget the towels!  You'll want to dry off the cans and bottles after placing them in the water. 

Secondly, I had the students create a T-Chart on a white sheet of paper.  As the kids placed their bottles and cans on the table to add to our collection, they wrote down each one on the left hand side of the paper.  On the right hand side, they wrote their hypothesis as to whether each beverage would sink or float. 

Next, the students put the bottles and cans into the water and we gave an X on the paper if they did not predict correctly. 

After the placing of the beverages, we talked about the reasons why some beverages floated better than others.  (Some were in between  floating and sinking.)  Bottles vs. cans of the same type of beverages was an interesting conversation as was sugared drinks vs. diet drinks. 

Overall, the kids really liked it, and it can almost be turned into a health lesson (sugar vs. sugar substatute vs. water based beverages).