HOW TO PROVE WATER VAPOUR IS PRESENT IN AIR???

Do you know water vapour is present in the air?? Water vapour is a gaseous form of water. Let's prove that water vapour is present in air?
Materials:
Clean glass tumbler
Dry towel
Ice cube

Instructions

Wipe the outside of the glass with a clean dry towel to ensure it is dry from the outside.


Place a few ice cubes inside the glass and wait for a few minutes.


Observe: You would notice the outside of the glass turns misty and finally droplets of water appear on the outside of the glass


HOW DOES THE WATER COMES OUTSIDE THE GLASS???


This happens because of condensation. Water vapor is present in air and when comes contact with cold objects changes into liquid form

FAKE BOILING WATER WITH FRICTION!!!

Can you make water boil with friction? Sounds tough but is easy! (you would need a friend for this experiment)


Materials:
A small jar around 5cm wide
Water
Two 15cm square cheesecloth pieces 
A wide rubber band 
Cover the top of the cloth with two pieces of cheesecloth and use the rubber band to keep the cheesecloth in place.


Pour the water into the glass through the cheesecloth and make sure to wet the cheese cheesecloth thoroughly.


Then quickly turn the glass upside down. Don't worry the water won't fall down unless you did not make the cloth thoroughly wet while putting water into the glass through the cheesecloth.


Now ask your friend to rub his hand on the piece of fabric until his finger becomes hot by friction.


Continue to hold the glass upside down and ask your to put his/her finger which he/she had warmed on the cheesecloth.


Observe: Bubbles rise up from the spot where your friend had touched!!

How did the bubbles come?!?!

The bubbles you saw were air bubbles that had been trapped between the fibers of the cheesecloth. When your friend touched the cloth the air was forced up into the water because of the heat!

How did the water stay in the glass when you turned the glass upside down?!?!

When you poured water through the cheesecloth into the glass the tiny openings in the cloth were filled with water, Water molecules formed in the cheesecloth were strongly attracted to each other.

They formed an invisible skin known as water tension in each small space space that has air. The water tension was strong enough to hold the water inside the jar!!!!