Floating an egg in water

We had two containers filled with tap water. We added salt to one container and found that our egg floated in the salty water but not in the plain water.
The children had to think and share amongst themselves as to why this happened.
We decided that adding salt changed the water and made it 'heavy' and the egg was light enough to float in it.

Floating and sinking

Room 3 tried floating and sinking plastic bottles-first with nothing in them,then with water in.

We didn't have much luck sinking those in our school pool!

Then we made some predictions as to which household items might sink or float.

Most children were surprised when a tennis ball,lemon and apple all floated-we talked about them having lots of air inside to be able to do this and their weight compared to water.