Atmosphere (paper 2) Flashcards
5 main gases in very early atmosphere (4.6 billion years ago)
Carbon dioxide, water vapour, nitrogen, methane, ammonia
True or false, for the last 200 million years, the proportions of gases in the atmosphere have mainly stayed the same
True
(With around 80% nitrogen and 20% oxygen and a tiny % of CO2, water vapour, noble gases and other gases)
For roughly the last how many years have the proportions of gases in our atmosphere stayed the same
200 million years
How many years ago was the Earth’s early atmosphere (first one)
4.6 billion years ago
% composition of today’s atmosphere (has been the same for roughly the last 200 million years)
78% nitrogen
21% oxygen
0.9% argon
0.04% carbon dioxide
Trace amounts of other gases
% of nitrogen in todays atmosphere
78%
% of oxygen in today’s atmosphere
21%
% of carbon dioxide in today’s atmosphere
0.04%
% of argon in today’s atmosphere
0.9%
Main gas in today’s atmosphere and what % is it
Nitrogen
78%
The Earth’s very early atmosphere was formed by what activity
Volcanic activity
3 key gases released by volcanoes (volcanic activity in early atmosphere 4.6 billion years ago)
Carbon dioxide
Water vapour
Nitrogen
(Methane and ammonia were also present)
The Earth’s early atmosphere was very likely similar to the atmospheres of what 2 planets today
Venus and Mars
True or false, the early atmosphere was very similar to today’s atmosphere of Venus and Mars
True
How did oceans first form in the Earth
The large amount of water vapour in the early atmosphere condensed as the Earth cooled
First reason why carbon dioxide levels reduced in early atmosphere
As the Earth cooled, the water vapour condensed to form oceans
CO2 could then dissolve in this
When did algae start to appear
2.7 billion years ago
What major thing started to appear 2.7 billion years ago
Algae
What important process did algae and other green plants carry out when they first evolved 2.7 billion years ago
Photosynthesis- led to slow increase in oxygen and decreased CO2
In the first billion years the gases that formed the earth’s atmosphere came mainly from which source
Volcanic activity
What is the atmosphere
A layer of gases surrounding the Earth that’s held in place by gravity
3 greenhouse gases
Water vapour
Carbon dioxide
Methane
What is the greenhouse gas effect
Greenhouse gases allow short wavelength EM radiation (e.g UV light) to pass through the atmosphere from the sun to the Earth
Energy is absorbed by the Earth’s surface
Energy is then re-emitted at longer wavelengths e.g IR
Before it can get back to the sun some of the energy is absorbed by greenhouse gases in the Earths atmosphere
This traps the energy so increases the temperature
Global warming definition
Increase in average temperature of the Earth’s atmosphere
Why is it difficult to make predictions about the atmosphere
It is so big and complex
What was formed when carbon dioxide dissolved into the oceans
Sedimentary rocks like limestone
True or false, carbonates and sedimentary rock are the same thing
True
They were formed from CO2 dissolving in the oceans and reacting with the water
After algae evolved, the oxygen allowed more plants to evolve.
What is the carbon in them locked up as when they die
Fossil fuels like coal
Carbon footprint meaning
Amount of carbon dioxide released into the atmosphere as a result of an individual’s activities
Greenhouse gas simplified definition
Trapping of heat inside the Earth’s atmosphere due to increased levels of greenhouse gases
1 advantage of greenhouse effect
Allows earth to be warm enough for life to occur
4 pollutants released in combustion of fuels
Carbon monoxide
Sulfur dioxide
Oxides of nitrogen
Particulates e.g soot
What 2 pollutants cause acid rain
Oxides of nitrogen
Sulfur dioxide
What pollutant leads to global dimming
Particulates e.g soot
What key event lead to an increase in % of oxygen in atmosphere
Algae evolving around 2.7 billion years a go
How is Sulfur dioxide formed
Reacts with oxygen at high pressure and temperature
(Sulfur impurities are in fuels and oxygen is in the air)
How are nitros oxides formed
Nitrogen and oxygen (both in air) react at high pressures and temperatures e.g from car engines
Which 2 pollutants cause acid rain
Sulfur dioxide
Nitrous oxide
How acid rain is formed
Sulfur dioxide/ nitrous oxides dissolve in clouds to form dilute Sulfur/ nitric acid which falls as acid rain
2 effects of nitrous oxides/ Sulfur dioxide
Cause respiratory problems
Cause acid rain
2 effects of particulates
Global dimming
Respiratory problems
