Try this Mini Miss Hide and Sink experiment in your own home.

What to do:

1. Gather together all the objects you want to test.
2. Fill the bath half full with water.
3. Both you and your friend should pick one item each that you think will sink.
4. One at a time, place it in the bath. If it sinks you get a point, if it floats you get nothing.
5. Remove those items from the bath and place on the towel - they are now out of play.
6. Choose another object each and try again.
7. Keep on going until you have tested all the items.
8. The person with the most points at the end wins.

For something to float it has to push aside an amount of water that weighs the same or more than it does. Basically, the whole of the object and the air trapped inside it has to be less dense than water. And it's the opposite for sinking. For an object to sink it has to be more dense than water.

While some of your objects look light, water may be allowed to flow into them so adding to their weight and making them more dense than water, causing them to sink.