Air is everywhere
Let us take an empty glass bottle. Is it really empty or does it have something inside?
Now, shall we turn the glass bottle upside down? Can you agree that there is still something inside the empty glass bottle? Let us do the following activity to find what is there inside an empty glass bottle.
Dip the open mouth of the bottle into the trough filled with water as shown in Fig 1. Observe the bottle. Does water enter the bottle? _______
Now tilt the bottle slightly. Now again dip the open mouth of the bottle as shown in Fig 2. Do you think that water will enter the bottle? _______
Kindly observe the Fig 2 carefully. You can see bubbles coming out of the bottle. When you perform the experiment, can you hear the bubbly sound? can you now guess what was inside the bottle? _______
Yes, you are right. It is “air” that was present in the bottle.
The bottle was not empty at all. In fact, it was filled completely with air even when you turned it upside down. That is why we notice that water does not enter the bottle when it is pushed in an inverted position, as there was no space for air to escape.
When the bottle was tilted, the air was able to come out in the form of bubbles, and water filled up the empty space that the air has occupied.
Hence we can see that air fills all the space inside the bottle.
