CHEMISTRY OF THE ATMOSPHERE

Question 1

How do scientists think the early atmosphere was formed?

Answer 1

Surface used to be covered in lots of volcanoes which erupted and released lots of gases

Question 2

What gases was the early atmosphere probably made up of?

Answer 2

Lots of carbon dioxide
Almost no oxygen

Question 3

What gases do volcanoes release?

Answer 3

Nitrogen
Water vapour
Small amounts of methane and ammonia

Question 4

How were oceans formed?

Answer 4

When water vapour in the atmosphere condensed

Question 5

How was carbon dioxide removed from the early atmosphere (oceans)?

Answer 5

It was dissolved in the oceans and went through reactions to form carbon precipitates that formed sediments on the seabed

Question 6

How was carbon dioxide removed from the early atmosphere (plants)?

Answer 6

Green plants and algae evolved and absorbed some of the carbon dioxide for photosynthesis

Question 7

How does carbon become locked up in rocks and fossil fuels after organisms die?

Answer 7

Plankton and marine animals die and fall to seabed
Buried by layers of sediment
Become compressed and form sedimentary rocks, oil and gas (and trap carbon)

Question 8

How is crude oil and natural gas formed?

Answer 8

Formed from deposits of plankton (under seabed when trapped in rocks)

Question 9

How is coal formed?

Answer 9

Sedimentary rock made from thick plant deposits

Question 10

How is limestone formed?

Answer 10

Sedimentary rock made from calcium carbonate deposits from shells and skeletons of marine organisms

Question 11

What increased oxygen levels in the atmosphere?

Answer 11

Production of oxygen by photosynthesis from green plants and algae

Question 12

What are some greenhouse gases?

Answer 12

Carbon dioxide
Methane
Water vapour

Question 13

What do greenhouse gases do?

Answer 13

Act as an insulating layer in the Earth’s atmosphere

Question 14

What do greenhouse gases do in our atmosphere?

Answer 14

They don’t absorb incoming short wavelength radiation from the sun
Instead they absorb the long wavelength radiation that gets reflected back from earth
They re-radiate this longwave thermal radiation in all directions (like back to Earth)

Question 15

What are some forms of human activity that affect the amount of greenhouse gases in the atmosphere?

Answer 15

Deforestation
Burning fossil fuels
Agriculture
Creating waste e.g. landfill sites. decomposition

Question 16

What could be the consequences of an increase in global temperatures?

Answer 16

Polar ice caps melting causing rise in sea level, flooding and coast erosion
Frequency and severity of storms may increase
Changes in temp and water availability may affect species and distribution
Change in rainfall pattern and temp so may affect the ability to grow certain foods

Question 17

What are carbon footprints?

Answer 17

A measure of the amount of carbon dioxide and other greenhouse gases released over the full life cycle of something (service, event, product)

Question 18

What are ways to reduce a carbon footprint?

Answer 18

Use renewable or nuclear energy sources instead of fossil fuels
Use more efficient processes that conserve energy and cut waste
Governments could tax companies based on the amount of greenhouse gases they use
Technology that captures co2

Question 19

What are the limitations of reducing carbon footprint?

Answer 19

Could affect economic growth
Technology needs to be more advanced
Hard to make international agreements as most countries do not want to sacrifice their economic development
Not enough education/people do not want to change everyday lifestyle

Question 20

What happens during combustion of hydrocarbons?

Answer 20

Carbon and hydrogen in hydrocarbons are oxidised so that carbon dioxide and water vapour are released into the atmosphere

Question 21

What do fossil fuels contain (crude oil, coal etc.)

Answer 21

Hydrocarbons

Question 22

When does complete combustion occur?

Answer 22

When there is plenty of oxygen

Question 23

When does incomplete combustion occur?

Answer 23

When there is not enough oxygen

Question 24

What happens during incomplete combustion?

Answer 24

Solid particles (particulates) of soot (carbon) and unburnt fuel are released and carbon monoxide is produced (and sometimes co2)

Question 25

What problems can particulates in the air cause?

Answer 25

Can get stuck in lungs and cause respiratory problems
Bad for environment as they can reflect sunlight back into space so less light reaches Earth (global dimming)

Question 26

What is carbon monoxide?

Answer 26

Colourless, odourless, dangerous gas

Question 27

What does carbon monoxide do to the human body?

Answer 27

Binds to haemoglobin in blood so less oxygen is able to be transported around the body causing fainting, a coma or even death

Question 28

When is sulfur dioxide produced?

Answer 28

During combustion of fossil fuels that contain sulfur impurities

Question 29

What happens to the sulfur in sulfur dioxide during combustion?

Answer 29

It becomes oxidised

Question 30

How is nitrogen oxide produced?

Answer 30

When a reaction between nitrogen and oxygen in the air caused by heat of burning

Question 31

What happens when sulfur dioxide mixes with clouds?

Answer 31

Produces dilute surfic acid which falls as acid rain

Question 32

What happens when nitrogen oxide mixes with clouds?

Answer 32

Produces dilute nitric acid which falls as acid rain

Question 33

What can acid rain do?

Answer 33

Kills plants
Damages buildings and statues
Corrodes metal

Question 34

How are sulfur dioxide and nitrogen oxide bad for humans?

Answer 34

Cause respiratory problems when breathed in