1. THE PROPERTIES OF AIR

2. And other gases: Carbon dioxide, Argon, Ozone
The atmosphere is composed of air. Air is made up of a mixture of gases and water vapour.
COMPOSITION OF GASES:
NITROGEN 78%
OXYGEN 21%
And other gases: Carbon dioxide, Argon, Ozone

3. The properties of air are affected by heat from the surface:
TEMPERATURE
The properties of air are affected by heat from the surface:
When air is heated it
expands, becomes lighter
and rises.
The temperature lowers
as the air moves further
away from surface

4. TEMPERATURE
When it is cooler, the air begins to move back towards the surface
This process only occur in the troposphere.

5. RELATIVE HUMIDITY
Is the amount of water vapour that air contains. This is variable
Warmer air can hold more water vapour
There is a maximum of water vapour
If the maximum exceeded the vapour begins to condense and forms clouds.

6. Atmospheric pressure The gases have weight.
This weight presses down on the surface
Atmospheric pressure is the weight of the air that presses on the Earth.
The atmospheric pressure changes with altitude and temperature

7. air pressure

8. The atmosphere and life on Earth
Functions of the atmosphere:
Protect us from the Sun
Provide us with some important gases for Photosynthesis and respiration
Build an ozone layer in the stratosphere to protect us from the ultraviolet rays

9. PROTECTS THE Earth from space objects like meteors (desintegrating them )
Provide important gases for life:
Oxygen (O2): respiration
Carbon dioxide(CO2): photosynthesis and to maintain the Earth temperature by stopping heat from escaping- NATURAL GREENHOUSE EFFECT.

10. NATURAL GREENHOUSE EFFECT

11. Notes Quiz What is the most abundant gas in our atmosphere?
2. What are some trace gases that are in our atmosphere? (name 3)

12. 4. What are some of the solid particles in air? (Name 4)
3. What is ozone? a) It’s liquid oxygen b) It’s an oxygen molecule with 3 atoms of oxygen instead of 2 c) It’s a form of rust
4. What are some of the solid particles in air? (Name 4)

13. 5. Why would there be more water vapour in a tropical rain forest than in a desert? a) the climate is wet in a rain forest and a lot of water would evaporate b) there would be a lot of transpiration from the trees c) both a and b

14. 6. What is air pressure?
7. How is air pressure affected by altitude? 8. Does air have mass? Tell an example where you can see that air has mass.