Lesson 1
Finally managed to sign in after ten million tries because that bimbo gave me the wrong login id. -.-
Composition and Structure of the Air
We need to know this because it is essential for our living.
Composition of Air
Nitrogen 78%
Oxygen 21%
Carbon Dioxide 0.036%
Hydrogen
Methane
Sulphur Dioxide
Noble Gases
Trace Gases
Water Vapour
Carbon Dioxide, water vapour, Sulphur Dioxide and Methane are all variable gases, because their compositions in the air are not fixed. For example, methane is apparently cow fart, so on a farmland -> more cows -> more farts -> more methane.
Nitrogen
Most prominent gas in the air.
Main source of nitrogen is from volcanic eruptions.
Nitrogen is important because it provides us with energy as can be illustrated from the nitrogen cycle which goes as follows:
Atmosphere -> Soil -> Plants -> Us/Animals (and when we die we decompose and the nitrogen goes back to the atmosphere and the soil)
Oxygen
Used in repiration
Given out during photosynthesis
Carbon Dioxide
Regulated by the Carbon cycle.
Traps heat (Greenhouse effect, which is good unless it is an advanced greenhouse effect. That is bad.)
Methane
Traps heat (Greenhouse effect)
Structure of the air
Troposphere
Tropo in Greek means to mix or to blend
Sort of represents the weather. The composition of air above is found in the troposphere. (Note that different layers have different compositions of air.)
Stratosphere
Ozone layer
Protects us from UV rays
Mesosphere
Meso - middle
Thermosphere
It is the hottest layer. Hottest molecules can go up to 2000 degrees Celsius.
The mesosphere and thermosphere protects us from meteorites.
Meteorites burn up in the meso and thermosphere before it hits earth. That is why the Earth has no craters unlike the moon, because the moon has no atmosphere.
The atmosphere also ensures stable temperatures. On the moon, temperatures in the day can go up to 200 degrees Celsius and on the night it can go to as low as -200 degrees Celsius.
The atmosphere traps heat and blocks heat. It also absorbs and reflects radiation. Half of the rays are reflected.
The heat we have at night is trapped heat. Without the atmosphere, a blanket will surely not be enough to keep us warm.
Moving air - wind. The wind transfers heat to the colder parts of the earth like the poles. That is why extreme temperatures will not affect us too much.
In conclusion, the atmosphere
1. Protects (meteors, UV, too much solar radiation)
2. Acts as in insulator (thus ensuring stable temperatures)
3. Provides us with wind (transfers heat)
Misc:
Smell of burnt wire - smell of ozone layer
Smelling too much of it is poisonous and can cause respiratory problems (MATTHEW AND NIGEL TAKE NOTE)
Reflections (because Miss Lin said to add it)
The atmosphere is very interesting. Because uhm it rocks.
Okay but seriously, I never knew how important the atmosphere was until today. So I feel that the world should make a greater effort to slow down the speed of global warming! Also use more CFC-free products so as not to destroy our precious ozone layer. You don't want some meteorite to come crashing down in our classroom during a VERY INTERESTING geography lesson huh? (;
And the world will be no fun if everybody had skin cancer.
(Oh no, I think I'm gonna fail this reflections thing. /:)
-Nadine (:
posted by 08IP04/JH404 @ 4:46 AM
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