Elemental Rock, Paper, Scissors

by Left-field Designs in Living > Toys & Games

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Elemental Rock, Paper, Scissors

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This one is an old and simple science experiment most teenagers will have done at school.
Before I start let's deal with safety: This instructable deals with fire, please be careful when working with fire and if you are not a grown-up please get one to help.
We are about to play a game of elemental rock, paper, scissors
You will need:
A large, flat bowl
A large glass or jug
A small candle or dish with a cotton ball
A fire source
Water (I added blue food colouring because it just makes it cooler)

The Process

Elemental rock, paper, scissors

Fill your bowl with the water and place your candle or small bowl of cotton balls in so they are floating around.
Light your floating material on fire.
Use the large glass to cover the bur ingredients object and wait a second.
The flame will die down and then the liquid will get sucked from the bowl up into the glass.

Why It Works

Floataion: To start with water extinguishes fire so we need to separate them, in my case the little dipping bowl does nicely. The bowl floats due to buoyancy, this is where the displacement (the equivalent about of liquid pushed out of the way buy the object) has a greater mass than the object itself so it is pushed up.
Fire: fire needs 3 things, an ignition source, a combustible material and oxygen
When we place the jug over the burning material we limit the amount of oxygen available and the flame quickly consumes it, about 20% of the air around us is oxygen, the rest is made up of nitrogen, carbon and other periodic elements.
When the oxygen is consumed, this creates a vacuum, and nature does not tolerate a vacuum. This causes suction that pulls in the water. Our old friend buoyancy comes back into play ans the candle or burning material stays on top of the rising liquid level.

So back to the game,

  • Water extinguishes fire
  • Fire consumes oxygen
  • Lack of oxygen sucks up water