This vacuum chamber really sucks!
In this hands-on activity, you’ll make your own vacuum chamber and watch marshmallows turn into fluffy clouds of sugar!
*If you can’t find one to borrow, you can buy these from some liquor stores and homeware stores.
Air might seem like empty space, but it’s actually packed with molecules. In one teaspoon of air, there’s about 100 million million million moving molecules! These molecules bang and crash into surfaces, and the pressure of these pushing molecules is known as air pressure.
Marshmallows are filled with tiny bubbles, and the air molecules in the bubbles are pushing against the marshmallow. Usually, that’s balanced by the pressure of air outside the marshmallow.
When you place the marshmallow in a bottle and start pumping, you reduce the number of air molecules – and therefore the air pressure – surrounding the marshmallow. As air in the bottle is removed, the air molecules inside the marshmallows can push harder in comparison, so the marshmallow pushes out and takes up more space.
As you take the plug off, air molecules rush into the bottle. The molecules push hard on the marshmallow and shrink it back down again. The marshmallow will probably end up a bit smaller than at the start – some of the bubbles in the marshmallow will pop, making it a bit less aerated.
Check out this video about suction
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30 June, 2019 at 6:21 pm
This activity also works with vacuum food saver containers such as the ones recently given away at Coles. If you have a set, give it a try!