KS3 Pressure in Gases

Which of the three images represents the particles in a gas?

• A

• B

• C

A slight problem with this diagram is that the particles in a real gas are actually...

• in a neat arrangement

• closer together

• further apart

• not really there

What are the particles in a gas doing?

• Vibrating from side to side

• Drifting slowly in random directions

• Moving quickly in the same direction

• Moving quickly in random directions

• Not moving

The particles in a gas move around quickly because they have lots of .....................

When particles collide with the walls of their container they cause pressure.

Which two of these would increase the pressure?

• Adding more particles

• Making the particles lighter

• Making the particles move faster

• Making the container larger

• Slowing the particles down

When a gas is compressed the pressure increases because the particles collide with the container walls more...

The pressure in a balloon increases as the temperature rises.

Which of these is NOT a reason why?

• The gas particles hit the walls with more force

• There are more collisions with each cm² of wall per second

• There are more particles in the box to hit each cm² of wall

• On average, more force is applied to each cm² of the wall

When you breathe in, your chest expands and your diaphragm moves down. This causes your lungs to increase in volume. What will happen to the air pressure inside?

• It will increase

• It will decrease

• It will stay the same

Write some sentences to explain why the balloon shrinks when placed in the ice-cold water. Use as many key words from the boxes as you can.