Here's what we did. . .
We got our supplies and we learned how to use a graduated cylinder accurately so they could fill their cups with exactly 150 ml of water.
We then reviewed our experiment sheet . . .
. . . we practiced using a timer (some kids had their ipods and were SO excited that I let them use them! Those groups with no ipods used a visual timer on the Smartboard).
We then worked in small groups to try to come up with an answer about how the size of the "chunks" would affect how quickly they would dissolve in water. Remember, we have talked about particles, how they are always moving, how temperature affects their rate of movement, and so on. So--what kind of chunks are we talking about?
That's right--plop, plop, fizz, fizz! The kids were pretty excited to check it out. We made our "variable" the size of the chunk--we used a whole tablet, a tablet broken into 6-8 pieces, and a tablet ground into a powder. I did my not-so-gentle reminder about never tasting science, and so on and then we worked. We hypothesized and discussed procedures and off we went to experiment and observe!
It was so much fun to watch them cooperate as a science "team"--checking for procedures and to make sure everything remained constant. We finished up with a discussion about our conclusions and our thoughts about WHY things happened the way they did. I think I'll write this lesson up in case anyone would like it--it sure was fun and an easy one to prepare for! Have a great weekend, everyone!