Properties of air

1. Atmosphere

The atmosphere is composed of air. Almost all water vapour and 80% of the gases are contained in the lowest

level, the troposphere, which is in contact with the surface of the earth.

The high content of gas and water vapour mean the most meteorological phenomena, such as cloud formation,

wind and rain occur at this level.

2. Temperature

The properties of air are affected by heat from the earth’s surface. When air is heated it expands,

becomes lighter and rises.

Air temperature becomes colder as it gets farther from the Earth's surface.

When it is cooler the air begins to fall back towards the surface.

3. Air Humidity

Is the amount of water vapour in the air.

It is caused by evapotranspiration of water from oceans, lakes, rivers, wetlands and plants.

Air can contain water depending on its temperature. the hotter the air the more water can contain.

Relative Humidity measure the capacity of water that the air can contain.

Condensation

When water vapour cools, it condenses: It becomes liquid and forms small drops.
These drops forms clouds and fog.

3. ATMOSPHERIC PRESSURE

The gases in air have weigh that presses down on the Earth's surface. Atmospheric pressure is the
term used to describe the pressure exerted on Earth by the weight on the air. It is measured with a
barometer.

Both altitude and temperature determine atmospheric pressure.

TEMPERATURE                           ALTITUDE

EXPERIMENT: LOW DIFFICULTY 1. Introduce a can of soda in the freezer for 10 minutes, take out the can and record until you see the effect it produces (if it is hot in the room the effect will occur sooner), Describe and explain the results.bring the video to class!! 2. Place a hot drink pot near of a window, after this take pictures or record a video explaining what happens. 3. Record what happens when we put a casserole of water on the vitroceramic. If you put a glass lid on its top, what would you see in it? EXPERIMENT: HIGH DIFFICULTY 1 RELATIVE HUMIDITY 2. AIR TEMPERATURE 3. AIR PRESSURE

class activities and test