2. • According to the kinetic theory
of gases, gases are made up of
tiny and discrete particles.
• The particles in air move about
randomly at high speed.
The kinetic theory of gases
3. • Air has mass, so the atmosphere
pushes all things on Earth.
• The ‘pressing down’ of the
atmosphere on Earth is called air
pressure or atmospheric pressure.
• Why does we do not feel this
pressure…
Air exert pressure
4. • Air pressure is varies from place to place.
• Is the air pressure at higher altitude is
the same as lower altitude
• In a closed container, the particles of air
which collide with the walls of the
container also exert pressure on the wall
s of container.
5. • Volume
– Volume ↑, Pressure ↓
• Temperature
– Temperature ↑, Pressure ↑
Factors affecting air pressure
