Try this simple burning candle experiment using two glasses and a candle. Learn how oxygen, heat, and air pressure work in this easy science demonstration.
The burning candle experiment is a classic science activity that demonstrates how oxygen, heat, and air pressure interact inside a sealed container. Using only two drinking glasses, a small candle, and a piece of damp blotting paper, this simple experiment creates an airtight seal and shows what happens when a flame uses up the available oxygen.
As the candle burns, it consumes the oxygen inside the glass while heating the surrounding air. When the flame goes out and the trapped air cools, the air contracts, creating lower pressure inside the glasses. This pressure difference causes the two glasses to stick tightly together, providing a fascinating demonstration of basic physics and atmospheric pressure.
Originally featured in The Pathfinder, this vintage experiment remains a popular educational activity for classrooms, homeschool science lessons, and anyone interested in simple hands-on demonstrations using everyday household items.
Safety Note: Adult supervision is recommended. Perform this experiment on a heat-resistant surface, keep flammable materials away from the flame, and allow the glasses to cool before handling.
Burning Candle Experiment
A very interesting burning candle experiment may be performed with two drinking glasses, a small candle end and a piece of blotting paper, says the Pathfinder.
The glasses must be the same size and of the thin-glass kind. The candle end is lighted and set in one glass; the blotting paper is well dampened and placed on top of the glass, and the other glass inverted and its rim placed exactly over the lower one and pressed down tightly. The candle will burn up all the oxygen in the glass and go out.
The air in the glass being heated will expand and some of it will be forced out from under the moist paper, and then, as the portion remaining cools, it will contract and draw the upper glass on the paper and make an air-tight joint. The upper glass can then be taken up and the lower one will cling to it.
Excerpt from the book: The Boy Mechanic – BOOK 2 – 1000 THINGS FOR BOYS TO DO | Published, 1915 | Various Authors
