You will need:
- 2 balloons
- A lighter or match *adult supervision required*
- Blow up one of the balloons and tie it.
- Hold the lighter or match under the balloon – it should pop!
- Put some water into the balloon, enough to fill it when it is deflated.
- Blow up the balloon, with the water in it, and tie it.
- Hold the lighter or match under the balloon – this time it won’t pop! You’ve made a flame resistant balloon!
The science bit:
- The first balloon popped because the flame heated the latex in the balloon until it melted and the balloon popped. But why didn’t this happen when there was water in the balloon?
- Water is a great conductor, as the water closest to the heat source gets heated, it rises to the top, leaving cool water at the bottom again – this is called convection. This creates a cycle so there is always cool water closest to the flame, meaning the latex doesn’t get hot enough to melt!