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Egg In A Bottle

It’s a tight squeeze, but with the push of air, you’ll be able to pop the egg in the bottle like magic

Australian Curriculum links

  • Science > Chemical Sciences > Year 5 > ACSSU077

You’ll need

  • Hard-boiled egg, de-shelled (or an egg-sized water balloon)
  • Glass bottle with an opening slightly smaller than the egg (e.g. 1L juice bottle)
  • Hot water (just boiled is best!)
  • An oven mitt
  • Margarine

Try this

  1. Grease the opening of the bottle with the margarine.
  2. Fill the glass bottle with hot water and wait 10-15 seconds
  3. Put the oven mitt on and pour the hot water out of the bottle.
  4. Once the bottle is empty, stand it on a table and place the egg on the bottle opening.
  5. Watch what happens! Sometimes it can be a little slow, but be patient!

What’s happening?

The hot water in the bottle heated the glass. Once the water is poured out, the hot glass heated the air inside the bottle, making the air expand. Some of the air escapes through the neck of the bottle. When the egg is placed on the bottle opening, this creates a slight seal, with a lower air pressure inside the bottle than outside. Air will always try to move from an area of high pressure to low pressure, so the air outside the bottle tries to move inside the bottle where the pressure is lower and forces the egg into the bottle as it does so.

But how do you get the egg out again?

  1. Grease the opening of the bottle with margarine. Make sure there is margarine well inside the opening.
  2. Tip the bottle upside down above your head. Shake the bottle gently until the egg is sitting in the mouth of the bottle, sealing the opening.
  3. Blow sharply at the egg through the mouth of the bottle and be prepared to have egg on your face! This can take some practice.

What’s happening?

When you blow inside the bottle, this increases the amount of air inside the bottle, creating higher pressure.  This means the air outside the bottle is at lower pressure. The higher air pressure inside the bottle then tries to move to the area of lower pressure outside and forces the egg out of the bottle, sometimes with messy results.