Task-1:  

Bring 2 empty water bottles.

Take a plastic bottle with the lid tight and try to squash it flat.

Case-a: Why can’t you flatten it?

Case-b: Take the lid off the bottle. Try squashing the bottle now. Why can you flatten it?

Task-2:

1. Take a plastic bottle and remove the lid.
2. Take a marker and mark it exactly at half of the bottle at 2 places giving a minimum gap as shown in the picture, with the help of a scissor make holes at marked places.
3. Now take the lid of the water bottle, with the help of a scissor make a hole at the center of it. Take a balloon and close the hole marked on the bottle as shown in the picture and tape it.
4. Now close the water bottle mouth with the lid.
5.  Wrap the balloon to the lid of the water bottle.
6. Now try to press the bottle with your fingers at the holes we made, you will see a balloon inflating.

Why is the balloon inflating ?

Let's investigate air or gas:

Can we see the air or gas ?

Does it have any shape or size?

Do you think it can flow?

Bring a small plastic box and fill the marble balls as shown below (2 to 4 Marble balls should be in the box and close it with a cap).Now hold in your hand and shake it. How do you feel now?  

Properties of GAS