In the summer, I like to prep food ahead of time before the midday heat creeps in and makes the kitchen too hot to cook. Boiled eggs are one of those foods that are easy to make ahead of time.

Rich in protein and nutrients, eggs are a hearty food. Besides their health benefits, they are also great tools to demonstrate an egg-citing air pressure experiment.

For this, you will need: 2 birthday candles, a hardboiled egg that is shelled and a clear glass bottle (milk jug, a glass Starbucks Frappuccino bottle etc). The mouth of the bottle should be slightly smaller than the egg. You will also need a lighter or matches.

This experiment should be done with adult supervision. Boil an egg for 10 minutes and then peel off its shell once the egg has cooled. Place the two birthday candles securely in the top off egg. Have the glass bottle handy. Holding the bottom of the egg, light the candles and turning the glass bottle upside down, placing the candles slightly inside the bottle warming the air inside. After 15 seconds, use the egg as a plug at the mouth of the bottle. What happens?

When the candle enters the bottle the air molecules inside the bottle start to heat up. Heated molecules expand and some start to rush out of the bottle. When the egg is placed firmly to the bottle, the air pressure increases inside the bottle.   A candle requires oxygen to burn and in this enclosed space, the oxygen runs out fairly quickly causing the flame to be extinguished. Without the flame heating the air in the bottle, the air temperature starts to drop and this fluctuation causes the air molecules to condense. This quick warming creates an air pressure difference inside the bottle causing the egg to be sucked inside the bottle.

This experiment can lead to some fun trials on how to get the egg out of the bottle. It can also become a hunt for the right bottle size. This summer as the kids are out of school, get cracking on some science experiments; be sure to check out our Urban Parent archives for more fun science.

For more great things to discover – visit the Discovery Centre on Barrington Street in Halifax, check out their website or join them on facebook