Chemistry of the Atmosphere (C9) Flashcards
What gasses are present in the atmosphere today?
Oxygen Nitrogen Carbon Dioxide Water Vapour Argon (and other noble gassses)
What percentage of the atmosphere today is nitrogen?
78%
What percentage of the atmosphere today is oxygen?
21%
For how long have the gasses in our atmosphere been constant?
About 200 million years
How old is the earth?
About 4.6 billion years
(4600000000)
(4.6X10^9)
What contributed to the gasses in the early atmosphere?
Volcanoes (water vapour, carbon dioxide and nitrogen)
How did oceans form?
Water vapour cooled
Which planets did the Earth’s early atmosphere seem similar to?
Mars
Venus
What did volcanoes release?
Water Vapour Carbon Dioxide Nitrogen Methane Ammonia
What was the main gas in the early atmosphere?
Almost purely Carbon Dioxide and a bit of Nitrogen
Why did levels of CO2 fall in the early atmosphere?
As oceans formed CO2 dissolved into them (forming a weak acid)
Over time, this formed sediments of carbonate rock to form on the sea bed
Some carbon dioxide was also used to make corals and shells for organisms
What do corals and the shells of organisms form when they die?
Limestone
How did oxygen first form in the atmosphere?
Photosynthetic algae evolved (and then plants and animals)
When did oxygen begin to form in the atmosphere?
2.7 Billion years ago
How did algae effect the levels of CO2 in the atmosphere?
Lowered it as photosynthesis takes in CO2 as a reactant
How long do fossil fuels take to form?
Millions of years
What is meant by the term non-renewable?
If we continue to use the resource we will eventually exhaust all the sources
What does coal form from?
Remains of ferns and trees
What conditions are needed for ferns and trees not to decompose?
Marshy wetlands
What may cause ferns and trees not to decompose?
Lack of oxygen or acidic conditions
What conditions are needed to form coal?
High temperature and Pressure
What does crude oil form from?
Plankton
What conditions are needed for plankton not to decompose?
No oxygen present
What conditions are needed to form crude oil?
Crude oil
What does natural gas form from?
Plankton
What is the main hydrocarbon in natural gas?
Methane
Which two fossil fuels form in the most similar way?
Natural gas and crude oil
What are the three fossil fuels?
Coal
Natural gas
Crude oil
What do all fossil fuels contain?
Trapped carbon
How do fossil fuels end up with carbon?
It was in the carbon dioxide the organism took in from photosynthesis
What percentage of the atmosphere is water vapour?
It is variable depending on temperature
What percentage of the atmosphere is carbon dioxide?
0.04%
What percentage of the atmosphere is methane?
0.0002%
Name 3 Greenhouse Gasses
Methane
Carbon Dioxide
Water Vapour
What type of radiation travels towards Earth?
Short Wave-length
What happens to short-wave radiation?
Some is reflected by the atmosphere but most enters it easily and is absorbed
Why does short-length radiation generally pass through the atmosphere?
It does not interact with the gasses in it
What does the Earth do when it absorbs short wave-length radiation?
Radiates the energy as long wave-length radiation
What happens to long wave-length radiation in the atmosphere?
Some leaves, some reacts with the greenhouse gasses and this causes the energy to become trapped
What happens when energy is trapped in the atmosphere?
It warms up
Why is the greenhouse effect necessary?
It keeps the Earth warm enough for life to be sustained
What makes CO2 levels increase?
Burning fossil fuels and deforestation
What makes methane levels increase?
Cows Farting
Rice Paddy Fields
Effects of Climate Change
Melting Ice caps
More severe weather
Chang distribution of insects and their diseases
Forces Animals to move
Why do scientists subject their findings to peer review?
Detect False Claims
Why is it so difficult to create accurate models for climate change?
Too complex
What is a carbon footprint?
The total amount of carbon dioxide and other greenhouse gasses emitted over the full life cycle of a product, service or event
What events greatly increase carbon foot prints?
Heating homes
Driving Cars
Generating Electricity
How can we lower emissions produced by heating homes?
Less warm
More insulators
How can we lower emissions produced by driving cars?
Public Transport
How can we lower emissions produced by generating electricity?
Energy efficient appliances
Turn appliances off
Switching to renewable sources
What are two of the main reasons people are reluctant to make eco-friendly switches?
Convenience
Cost
What are the biggest sources of methane?
Agriculture
Landfills
How can we more sustainable use the methane in landfills?
Trapping and burning it
What are the negatives of trapping and burning methane?
Cost
When do fuels release energy?
When Combusted
Give two examples of fuels
Coal
Hydrocarbons
What is coal often used for?
Generating electricity
What are hydrocarbons often used for?
Powering vehicles
What two elements do fuels contain?
Hydrogen
Carbon
General equation for complete combustion
Fuel + Oxygen -> Carbon Dioxide + Water
What type of reaction is combustion?
Oxidation
What happens if amounts of oxygen are too low during combustion?
Carbon Monoxide forms instead of carbon dioxide
What fuel most commonly contains sulphur?
Coal
When does sulphur Dioxide form?
Burning of coal
Oxidation
When do oxides of nitrogen form?
In engines
Why do we not specify which oxide is formed when nitrogen and oxygen react in engines?
A range of different molecules form
We call this NOx
What negative impacts do oxides of nitrogen and sulphur dioxide cause?
Dissolve to create acid rain
Creating breathing problems
What does acid rain commonly corrode?
Limestone
What is soot made off?
Particles of carbon and unburnt hydrocarbons
What type of pollution is soot?
Particulate
How do particulates damage human health?
Increase risk of heart and lung disease
Describe Global Dimming
Particulates limit the amount of energy from the sun that reaches the Earth’s surface
