Air is a matter of substance, and hence it contains weight and other assets like density and pressure.
Generally, the air surrounding us or objects does not show any pressure because it surrounds with equal pressure.
In this science activity, we will observe that air shows its pressure when the opportunity is given.Egg moving into the bottle without touching by external sources proves that air pressure is acting upon it. Let us discuss it in detail.Before the experiment begins, the pressure of the air surrounding and inside the jar is the same as it is equally distributed.That means the pressure inside and outside the glass bottle is the same at the beginning of the experiment.But when we placed the burning paper into the glass bottle, the air inside the jar starts to expand. Because air molecules expand when it gets warmed up, and this is the specific characteristic of air.And as soon as the egg is placed upon the opening of the glass bottle, the fire goes off, and the air molecules begin to cool down.As the air molecules cool down, they start contracting themselves by lowering the air pressure inside the glass bottle.That means there is a difference in the air pressure existing inside and outside the glass bottle.Because there is less air pressure inside the bottle. The egg slowly squeezes into the bottle as the outside pressure pushes it from outside.Yes, when the air molecules inside the bottle cool down, it offers more space to welcome additional air molecules.In this process, the outside air molecules rush into the bottle to fill the spaces. So, it keeps pressure on the egg and helps it slip down into the bottle.