Chemistry of the Atmosphere (Paper 2)

Question 1

What were the first few billions of Earth’s history like?

Answer 1

explosive - the surface was covered in volcanoes that erupted and released lots of gases. This is how the early atmosphere was formed

Question 2

What was the early atmosphere made up of?

Answer 2

mostly carbon dioxide, virtually no oxygen

Question 3

What did volcanic activity release?

Answer 3

nitrogen, water vapour, methane and ammonia. these built up in the atmosphere over time

Question 4

How were the oceans formed?

Answer 4

When the water vapour in the atmosphere condensed

Question 5

What happened to the carbon dioxide that caused it to be removed from the early atmosphere?

Answer 5

It dissolved into the oceans and went through a series of reactions to form carbonate precipitates that formed sediments on the seabed

Question 6

What were the earliest life forms to evolve?

Answer 6

marine animals - their shells and skeletons came from the seabed
green plants and algae

Question 7

What is coal made from?

Answer 7

a sedimentary rock made from thick plant deposits

Question 8

What is limestone made from?

Answer 8

a sedimentary rock made from calcium carbonate deposits from the shells and skeletons of marine organisms

Question 9

Which organism evolved first?

Answer 9

algae - about 2.7 billion years ago

Question 10

Why couldn’t animals evolve at the same time as algae?

Answer 10

Because the algae and other plants produced oxygen via photosynthesis, allowing other organisms to evolve later on when there was enough oxygen for them to survive

Question 11

What is the composition of the atmosphere today?

Answer 11

80% Nitrogen
20% Oxygen
other gases making up 1% - mainly CO2, noble gases and water vapour

Question 12

What are the main greenhouse gases?

Answer 12

Methane, CO2 and water vapour

Question 13

What is the purpose of greenhouse gases?

Answer 13

To act as an insulating layer in the Earth’s atmosphere - allowing it to stay warm enough to support life

Question 14

What type of wavelength of radiation do greenhouse gases absorb?

Answer 14

Not the incoming short wavelength radiation from the sun but the long wavelength radiation (thermal) that is reflected back off the Earth

Question 15

What happens to the radiation once it is absorbed by a greenhouse gas?

Answer 15

It is re-radiated in all directions

Question 16

What are the 4 human activities that affect the amount of greenhouse gases in the atmosphere?

Answer 16

• deforestation
• burning fossil fuels
• agriculture
• creating waste

Question 17

How does creating waste affect the greenhouse effect?

Answer 17

More landfill sites and more waste from agriculture means for CO2 and methane released by decomposition of waste

Question 18

Name 4 possible effects of climate change

Answer 18

• ice caps melting, rise in sea levels, increased flooding
• change in rainfall patterns, some places may get too little or too much
• frequency or severity of storms
• changes in temperature / amount of water which can affect wild species and differences in distribution

Question 19

Define carbon footprints

Answer 19

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

Question 20

What are 5 ways of reducing carbon footprints?

Answer 20

• renewable energy sources or nuclear energy
• using more efficient processes
• Government taxes on companies based on their greenhouse gas emissions
• Government caps on emissions allowed
• technology that captures CO2 produced before it is released into the atmosphere

Question 21

What are two examples showing that reducing CO2 emissions is easier said than done?

Answer 21

• carbon capture and storage technology is a new idea and it is still in the developmental stage
• many renewable energy sources eg solar panels are expensive. more development can make them cheaper

Question 22

Why are governments worried about reducing emissions?

Answer 22

it could have an impact on economic growth of their countries - especially for countries that are still developing

Question 23

Why is it hard to make international agreements about emission reductions?

Answer 23

not everyone wants to reduce emissions if it means sacrificing economic growth

Question 24

What are 3 ways an individual can make changes to their lifestyle to reduce greenhouse gas emissions?

Answer 24

• cycling or walking instead of taking a car
• reducing how much they use air travel
• anything that saves energy at home (eg turning down heating)

Question 25

Define a particulate in the air

Answer 25

a carbon particulate released into the atmosphere from incomplete combustion of a hydrocarbon

Question 26

How can particulates in the air cause problems?

Answer 26

• If inhaled they can get stuck in the lungs and cause damage
• Global Dimming, they reflect sunlight back into space so less light reaches the Earth

Question 27

How can carbon monoxide affect humans?

Answer 27

• it binds to the haemoglobin in the blood so less oxygen can be transported, causing fainting, comas and death
• it is colourless and has no smell so it is very hard to detect

Question 28

How can you test for sulfur impurities?

Answer 28

bubbling gases from combustion through universal indicator solution - if it turns red then sulfuric acid is present

Question 29

How is sulfur released into the atmosphere?

Answer 29

combustion of fossil fuels

Question 30

How can sulfur emissions affect the environment?

Answer 30

When mixed with water in clouds it forms acid rain which can damage statues and buildings, corrode metal and kill plants
Cause respiratory problems when breathed in

Question 31

How are nitrogen oxides released into the atmosphere?

Answer 31

Nitrogen and oxygen react in the air during combustion in cars

Question 32

How can nitrogen oxide emissions affect the environment?

Answer 32

When mixed with water in clouds it forms acid rain which can damage statues and buildings, corrode metal and kill plants
Cause respiratory problems when breathed in