Air, fortunately, is free and everywhere, which means there is no need to buy or search for it. So, let us enjoy three easy science experiments at home about air and its force, which is “atmospheric pressure”. All materials used could be easily found in any kitchen. The three activities are suitable for children, even for preschoolers, but all experiments must be conducted under the supervision of adults.
Experiment (1): Drip Drop
Bring a plastic bottle and drill little holes on its sides, preferably using a small screw, then fill the bottle with water. As long as the bottle is closed, the water will not come out of it, because the air prevents this. When you open the lid, the air will flow into the bottle and the water will come out of the holes. Watch the experiment here:
Experiment (2): Upside Down
Bring a cup of water and a piece of paper. Gently place the paper on the top of the cup, then flip it over with your hands still placed on the paper. Make sure that the water does not spill out, then remove your hand from the bottom. The paper sticks to the glass and the water will remain in the cup because of air pressure. Watch the experiment here:
Experiment (3): The Balloon and the Jar
This experiment is not suitable for children, and must be conducted under supervision. Bring one balloon, one glass jar, and matchstick; preferably, fill the balloon with water before blowing it, then tie it off. Now, light the matchstick and place it in the jar. Place the balloon over the jar carefully, and watch how it sticks to its top.
The reason is that air pressure outside and inside the jar are not the same. As the fire burns inside the jar, the air inside loses its oxygen, while the air outside remains as it is. The balloon by its turn separates the internal and external air, so it will let the air out but not in, which makes the balloon stick to the jar. Watch the experiment here: