Activity overview

Run the activity

1. Explain that today the class will need to make the tallest icy skyscraper they can using just ice cubes.

2. After 20 minutes (if they last that long!), swap towers with another group. Continue working but this time on their tower. How can they improve it?

3. After 10 more minutes, survey the final towers. What have they learned from swapping projects? 

Background science

Ice is slippery and not a great material for building! This activity offers a really fun way to demonstrate changes of state.
Water can exist in three states: solid (ice), liquid (water) and gas (steam). By changing the state of water (i.e. applying or removing heat) you change its properties. Imagine trying to construct a tower out of liquid water or steam!
As the class are building their towers they will notice the ice beginning to melt. The ice melts as it absorbs energy from the surrounding environment.  

We recommend you check your health and safety guidance before starting this activity. It's wise to minimise handling of the ice cubes or use gloves to avoid ice burns. 

Take it further

How would different sized or shaped blocks of ice change this investigation? Challenge your class to find out! Think more deeply about water and ice with the question What if water didn’t freeze?
Think about other practical uses for blocks of ice – igloos for example. What size and shape of blocks are used in this example? How are the conditions different for people who use ice as building blocks for real?

Try this fun investigation to see if your class can stop an ice lolly (or an ice cube) from melting.