Most substances become more dense when they become solid, but not water! This activity gives the children the opportunity to see how ice floats, discuss how frozen water becomes less dense and begin a discussion about changing states of matter.

set up ideas:
A large clear tub is a great way to ensure that everyone has a view of the ice. You may consider using ice dyed with Liquid Watercolor for extra visibility.

let's get started

For this activity, you'll need a tub of water, a container full of ice cubes and tongs for handling the ice cubes.

step 1
Place the tub of water on a table so the children can reach it easily.
step 2
Have the children place some of the ice cubes into the tub of water using the tongs.
step 3
Observe how the ice cubes float in the container. Have the children stick their hands into the water and brush underneath the ice cubes to verify there is nothing holding up the cubes but water.
step 4
Have the children push the cubes down into the water to observe how they bounce back up.

Unlike most substances, water becomes less dense when it becomes a solid. When water freezes and becomes ice, it is less dense than water and this is what allows it to float. This is a great way to introduce changing states of matter.
Tips and Tricks Tips and Tricks
With ice inside the tub, the water is going to be very cold. Be sure to have towels on-hand for children to quickly dry and warm their hands.
Follow Up ActivityFollow up Activity
Demonstrate how density affects whether an object floats in water using something very dense, such as a rock, and something less dense such as a foam block. Have children predict which items will float or sink.