Through this activity students will find out about how:
- Objects can keep their shape as the forces are balanced between air inside the object pushing outwards and air surrounding the object pushing inwards.
- Removing the air from a glass bottle will decrease the air pressure acting on the marshmallows, so there will be greater air pressure pushing out from inside the marshmallows. This will cause the marshmallows to expand.
- Altering air pressure in a sealed environment can have an impact on the shape of objects within that atmosphere.
- Reintroducing air to the bottle will increase the air pressure surrounding the marshmallows, which can make them change shape again.