1. Gas Pressure L/O :- To understand what causes gas pressure

2. Diffusion Look at the diagram which shows bromine gas and air contacting each other. The models show the direction the particles take - which one is correct? Bromine Air The cover was removed, and after about an hour the glass jar looked like this Cover Model 1 Model 2Model 3

3. What do you think happens when you pump up a football or rugby ball? How does this affect the pressure inside the ball? What is happening is happening to the particles inside the ball?

4. When gas particles hit the side of a container they exert a pressure. The more often the particles collide and the harder they hit the edge, the higher the pressure What do you think could increase how often the particles hit the side or how often?

5. What do the particles look like in a balloon? Why does it keep its shape when you blow it up? Why does it lose shape after a few days? Why can it pop if you blow it up too much?

6. How does heat affect gas pressure? Two balloons, of equal size, will experience different temperatures - one will be placed in some warm water, the other in cold water… What do you think will happen to the particles inside the balloon if it is heated? (hint: think about what the gas particles do when they get hot) What do you think will happen to the particles inside if the balloon is cooled? If a gas is heated up, its particles move around more quickly. They will hit the sides of the balloon harder, and more often. This will then increase the pressure (and the balloon expands) The opposite happens when you cool it - the particles move slower, crash into the sides with less force, and less often, decreasing the pressure (so the balloon shrinks) How could you test how temperature affects gas pressure?