Sink or Float?

C and R learned about predictions and observations this week when we made a sink/float bottle.

First, we gathered up a bunch of small items that we could fit into our bottle. I made sure that we had items made from wood, plastic, metal, and styrofoam.
We filled the bottle 2/3 of the way with water. C and R took turns dropping the items into the water. Before adding the items we made predictions as to whether the item would sink or float and then recorded our observations.

C is cheering because his prediction was accurate!

C and R took turns predicting and for R it was just a guess but C started to think about why some things would float and others would sink. I loved listening to his thought process. We talked about the items, what they were made of, whether they absorbed water and how that affected what happened, if at all.

C was curious to see what would happen if he turned the bottle upside down.

He then had to try turning the bottle on it's side.

Here are our predictions and observations:

Item - Prediction - Observation

• star plastic bead - sink - sink
• yellow plastic bead - sink - at first it floated but later sank
• dice (die actually, right?) - float - sink
• dime - sink - sink
• car - float - sink
• rubber band - float - sink
• pom pom - sink - it floated until it absorbed water and sank
• piece of sponge - float - float
• ribbon - sink - float
• metal paper clip - sink - sink
• plastic paper clip - sink - sink
• penny - sink - sink
• googly eye - sink - float
• packing peanut - float - float
• wooden clothespin - float - float

C and R enjoyed predicting and recording their observations. They were fascinated by this experiment.