C9 - The Chemistry of the Atmosphere

How old is the Earth?

4.6 billion years old

What percentage of the Earth's atmosphere is made up of nitrogen?

78%

What percentage of the Earth's atmosphere is made up of oxygen?

21%

Which gases make up less than 1% of the Earth's atmosphere?

Carbon Dioxide, Nobel gases and Water Vapour

In the first billion years of the Earth, what were the conditions like?

Dry and volcanic

Which three gases did early volcanic activity produce lots of in the atmosphere?

Carbon dioxide, Water vapour and NItrogen

Which other two gases did early volcanic activity produce in smaller quantities?

Methane and ammonia

4.6 billion years ago, what was the Earth's atmosphere mainly made up of?

Carbon dioxide

What happened in the first billion years of the Earth to lower the carbon dioxide in the atmosphere?

Water vapour condensed into the oceans and CO2 was dissolved

What was given out when the CO2 dissolved in the oceans?

Carbonate precipitates and sediments

What happened for the Earth's atmosphere 2.7 billion years ago?

Algae and green plants began to appear

When did algae and green plants appear?

2.7 billion years ago

What happened to the Earth's atmosphere with more algae and green plants?

CO2 rates declined and O2 levels increased due to photosynthesis

What happened when the green plants died?

They were buried under layers of sediment

What does sediment compress to form?

Sedimentary rocks, fossil fuels and oils

What forms crude oils and natural gases?

Dead plankton

What forms coal?

dead plant matter

What forms limestone?

Calcium carbonate that aquatic organisms use in their shells and skeletons

Why did early levels of CO2 decrease?

sediment/limestone formation from carbonates

What type of radiation does the sun emit?

short wavelength

What does the earth do to the short wavelength radiation when it passes through the greenhouse gases?

Absorbs it and re-emits it as longer wavelength radiation (infrared)

What two ways do humans increase the amount of CO2 in the atmosphere?

Increased combustion in factories

More deforestation

What two ways do humans increase the amount of methane in the atmosphere?

Increased cattle agriculture

Landfills

Why is peer review important (three things)?

Detects false claims,

Allows experimental evidence to be reproduced,

Encourages alternative hypothesises

Why do some people not believe climate change is caused by human activity (three reasons)?

Models and theories are oversimplified,

Views are gained from biased media,

There are natural fluctuations in the Earth's temperature

Name 6 pollutants

Carbon dioxide,

Carbon monoxide,

Water vapour,

Sulphur dioxide,

Nitrogen oxides,

Particulates

How is carbon monoxide formed?

incomplete combustion

How is sulphur dioxide formed?

Sulphur reacts with oxygen when a fossil fuel is burned

How are oxides of nitrogen formed?

When the nitrogen and oxygen in the air react together at high temperatures like in car engines

How are carbon particulates formed?

incomplete combustion

Effects of carbon monoxide

Poisonous, colourless and odourless gas that binds to haemoglobin over oxygen

Effects of sulphur dioxide

Acid rain and respiratory issues

Effects of nitrogen oxides

Acid rain and respiratory issues

Effects of particulates

Global dimming and respiratory issues

How do you test for hydrocarbons?

Add bromine and see if turns from orange to colourless

What does acid rain effect?

Statues, buildings and trees

Define weather

Short term atmospheric conditions

Define climate

Typical weather conditions in a region over a long period of time

When burning fossil fuels, how is sulfur dioxide formed?

Sulfur is an impurity in some fossil fuels and is oxidised when they're combusted

Define carbon footprint

the total amount of carbon dioxide and other greenhouse gases emitted over the full life cycle of a product, service or event

Define climate change

a change in global or regional climate patterns

What are the two reasons that global warming causes the sea level to rise?

Ice caps melting, water expanding

Difference between weather and climate?

weather is short term and localised and climate is long term patterns in weather

What form does the sun emit heat energy as?

short wavelength radiation

Issues with acid rain

Corrodes metals, damages buildings/statues, makes soil more acidic so plants can't grow

What pollutants cause global dimming?

Carbon particulates

What pollutants cause acid rain?

Sulphur dioxide and nitrogen oxides

What pollutants cause respiratory issues?

Particulates, sulphur dioxides and nitrogen oxides