1. LO: to explain pressure in gases
Air Pressure
LO: to explain pressure in gases
Starter: 1. Draw a balloon and show how the particles are moving inside it
2. What could I do to increase the pressure in this balloon?

2. Copy and complete this paragraph
We all live at the bottom of a “sea” of _____ called the a___________.
Gas particles are always _________ and _______ into the walls of container they are in. These collisions cause _________.
We can _______ the pressure and number of collisions by increasing number of particles and the speed they move at (energy).

3. Collapsing Can
-Pair work and answer in your book
As the can is heated the air in the can moves faster and there are more c______. When the can is placed in cold water it c________ because the particles……

4. Marshmallows (balloon) in a vacuum
At first the atmospheric pressure on the outside of the balloon ________ the air pressure inside the balloon. Then the air is sucked out, the outside pressure is ………..

5. Air pressure Magic trick
Bottle in a vacuum
1 There is pressure on the inside and the outside of this plastic bottle.
A What is causing the force? Explain as fully as you can.
B What can you say about the size of the pressure inside and outside the bottle?
C What will happen to the bottle as more and more air is taken out?
D Why will this happen? Explain as fully as you can
 2. A What makes the card stay up when the glass is upside down?
B This trick does not work if the glass is not completely full of water. Try to explain why. (Hint: think about what is in the part of the glass that is not full of water.)

6. Using pressure Sucking creates a negative pressure in the straw.
The high air pressure acting on the surface of the liquid pushes the liquid up the straw.

8. What will happen when air is sucked out of the bottle using a vacuum pump?
What will happen to the pressure inside the bottle?