C9 - Chemistry of the Atmosphere

Question 1

What are the percentages of gases in today’s atmosphere

Answer 1

Nitrogen - 80%
Oxygen - 20%
Carbon dioxide, noble gases, sulphur dioxide <1%

Question 2

What gases were released as a result of volcanic activity

Answer 2

Nitrogen, water vapour, methane and ammonia

Question 3

How were oceans formed

Answer 3

When water vapour in the atmosphere condensed

Question 4

What was the early atmosphere like

Answer 4

Mostly carbon dioxide with no oxygen

Question 5

How was lots of carbon dioxide removed from the early atmosphere

Answer 5

Dissolved in the oceans - then went through a series of reactions to form carbon precipitates that formed sediments on the seabed
Green plants and algae evolved and absorbed some of the carbon dioxide to carry out photosynthesis

Question 6

How were sedimentary rocks, oil and gas produced
(ppm seabed)

Answer 6

Plants, plankton and marine animals die, they fall to the seabed and get buried by layers of sediment. Over millions of years they become compressed and then form allat

Question 7

Describe how crude oil and natural gas are formed ( 1 mark)

Answer 7

Deposits of plankton

Question 8

How is coal made

Answer 8

Thick plant deposits

Question 9

What is the equation for photosynthesis

Answer 9

6CO2 + 6H2O → C6H12O6 + 6O2

Question 10

How was limestone made

Answer 10

Mostly made of calcium carbonate deposits from the shells and skeletons of marine organisms

Question 11

What is the purpose of greenhouse gases

Answer 11

Greenhouse gases in the atmosphere maintain temperatures on Earth high enough to support life.

Question 12

describe the greenhouse effect in terms of the interaction of short and long wavelength radiation with matter (4marks)

directions fr.

Answer 12

Greenhouse gases don’t absorb the incoming short wavelength radiation from the sun - they absorb the long wavelength radiation that gets reflected back off the earth - re-radiate it in all directions including back towards earth
Longwave radiation is thermal radiation so it results in warming of the surface of the earth - greenhouse effect

Question 13

Give 3 examples of greenhouse gases

Answer 13

Water vapour, carbon dioxide and
methane

Question 14

Describe how human activity affects the amount of greenhouse gases in the atmosphere ( 6 marks)

Answer 14

Deforestation - fewer trees means less CO2 is removed from atmosphere via photosynthesis
Burning fossil fuels - carbon that was locked up in these fuels is released as CO2
Agriculture - more farm animals produce more methane through their digestive processes
Creating waste - more landfill sites and more waste from agriculture means more CO2 and methane released by decomposition of waste

Question 15

Why is it hard to fully understand the Earth’s climate and what could it lead to

Answer 15

It is so complex and there are so many variables, that its very hard to make a model that isn’t oversimplified - led to speculation in the media where stores may be biased or only some of the information is given

Question 16

Describe the impacts of climate change ( 6 marks)

Answer 16

Increase in global temperature could lead to polar ice caps melting - causing a rise in sea levels, increased flooding in coastal areas and coastal erosion
Changes in rainfall patterns may cause some regions to get too much or too little water - along with the changes in temperature some regions may struggle to produce food
Frequency and severity of storms may also increase
Changes in temperature and the amount of water available in a habitat may affect wild species leading to differences in their distribution

Question 17

What is carbon footprint

Answer 17

A measure of the amount of carbon dioxide and other greenhouse gases released over the full cycle of something

Question 18

Describe 6 ways to reduce carbon footprint

Answer 18

Renewable energy sources or nuclear energy could be used instead of fossil fuels
Using more efficient processes could conserve energy and cut waste - lots of waste decomposes to release methane
Government could tax companies or individuals based on the amount of greenhouse gases they emit
Government could put a cap on emissions of all greenhouse gases that companies make
Usage of technology that captures the CO2 produced by burning fossil fuels before its released into the atmosphere

Question 19

Describe why reducing carbon footprint would be difficult (6 marks)

Answer 19

Making these changes will have an impact on the economic growth of communities - bad for people’s well being
International agreements to reduce emissions - most countries don’t want to sacrifice their economic development if they think that others won’t do the same
Individuals in developed countries need to make changes to their lifestyles

Question 20

What happens when there isn’t enough oxygen when burning fuels ( 3 marks)

Answer 20

some of the fuel doesn’t burn - complete combustion
Particulates of soot and unburnt fuel are released and carbon monoxide can be produced as well as carbon dioxide

Question 21

Describe the problems that particulates can cause

Answer 21

If inhaled - they can get stuck in the lungs and cause damage - lead to respiratory problems
Also bad for the environment - clouds they help to produce/themselves reflect sunlight back into space - less light reaches Earth - global dimming

Question 22

Describe the problems that carbon monoxide can cause (4 marks)

Answer 22

Stops blood from carrying oxygen around the body - by binding onto haemoglobin in your blood that normally carries 02 - less oxygen is able to be transported around the body
Lack of oxygen in the blood can lead to fainting, coma or death
Carbon monoxide doesn’t have any colour or smell so its very hard to detect making it even more dangerous

Question 23

What problems could sulphur dioxide and nitrogen oxide cause ( 2 marks)

Answer 23

Sulphur dioxide and nitrogen oxide
cause respiratory problems in humans and cause acid rain.