Atmospheric Chemistry

Question 1

What are the percentages in today’s atmosphere?

Answer 1

1% other gases - water vapour, noble gases, carbon dioxide

21% oxygen

78% nitrogen

Question 2

Why are carbon dioxide levels increasing?

Answer 2

Because we’re burning fossil fuels.

Question 3

Early atmosphere

Around __ billion years ago the earth was a ball of _____, hot rock.

The surface of the earth was made up at mainly __________, which released gases like carbon dioxide, ________ and water vapour into the atmosphere.

Answer 3

4.5
Molten

Volcanoes
Nitrogen

Question 4

How were oceans formed?

Answer 4

Water vapour cooling and condensing.

Question 5

How was oxygen produced?

Answer 5

Plants produced oxygen by photosynthesis.

Question 6

How did carbon dioxide decrease?

Answer 6

CO2 was absorbed by plants and algae.

CO2 dissolved in the oceans - impacting marine animals.

CO2 became ‘locked up’ in rocks and fossil fuels.

Question 7

Describe and explain how the earth’s atmosphere has changed over 4.5 billion years:
[6]

Answer 7

The early atmosphere had nitrogen, carbon dioxide and water vapour, whereas now it has oxygen and nitrogen.
This has happened because plants and algae have absorbed carbon dioxide, also carbon dioxide has been ‘locked in’ by rocks.

Another change is that the early atmosphere has no oceans, whereas now it does.
This has happened because, water vapour from the atmosphere has been condensed.

Finally, the early atmosphere also had no oxygen. However, now we have oxygen, so that we’re able to live on earth. This happened because plants produced photosynthesis, which gave out oxygen.

Question 8

Where does carbon monoxide come from, and what environmental impact does it have?

Answer 8

From: fuels not burning properly.

Impact: poisonous gas.

Question 9

Where does particulate come from, and what environmental impact does it have?

Answer 9

From: former as a byproduct of incomplete combustion.

Impact: global dimming.

Question 10

Where does nitrous oxides come from, and what environmental impact does it have?

Answer 10

From: burning fuels at very high temperatures.

Impact: effects on human respiratory system.

Question 11

Where does sulfur dioxide come from, and what environmental impact does it have?

Answer 11

From: burning fossil fuels that have sulfur in them.

Impact: acid rain.

Question 12

Where does carbon dioxide come from, and what environmental impact does it have?

Answer 12

From: burning fossil fuels.

Impact: greenhouse gases, heats up earth. (Global warming)

Question 13

Greenhouse gases like c______ dioxide, m_______ and water v_______ act like an i________ later in the earth’s atmosphere - this amongst other factors, allows the earth to be w_____ enough to support life.

Answer 13

Carbon 
Methane 
Vapour 
Insulating 
Warm

Question 14

All particles a______ certain frequencies of radiation.

Greenhouse gases _____ absorb the incoming s_________ radiation from the sun - but they ___ absorb the long-wave radiation that gets r________ back off the earth.

Then they re-________ it in all directions - including back towards the ________.

The long-wave radiation is ________ radiation, so it results in warming of the surface of the earth.

This is the ___________ effect.

Answer 14

Absorb

Don’t
Short-wave
Do
Reflected

Radiate
Earth

Thermal

Greenhouse

Question 15

Some forms of human activity affect the amount of greenhouse gases in the atmosphere:

(4 effects)

Answer 15

Deforestation - fewer trees means less CO2 is removed from the 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 process.

Creating waste - more landfill sites and more waste from agriculture means more CO2 and methane released by decomposition it waste.

Question 16

Greenhouse effect simplified:

1. Sun rays _______ earth’s atmosphere.
2. Heat is _______ back from the earth’s surface.
3. Heat is _______ by CO2 and as a result gets ________ in the atmosphere.
4. The earth becomes ________.

Answer 16

Enter

Reflected

Absorbed
Trapped

Hotter

Question 17

What are the effects of climate change?

Answer 17

Trapped energy warms earth
Icecaps melting
Sea levels rising (flooding)
Extreme weather 
Droughts
Some species go extinct 

An increase in global temp could lead to polar ice caps melting - causing a rise in sea levels, increasing flooding and coastal erosion.

Question 18

Propane + _______ -> carbon dioxide + ______

Answer 18

Oxygen

Water

Question 19

Changes in rainfall patterns (the amount, timing and distribution) may cause some regions to get too much or too little ______.

This’ along with the changes in _______, may effect the ability of certain regions to produce food.

Answer 19

Water

Temp

Question 20

The frequency and severity of storms may increase:

Answer 20

Changes in temp and amount of water available in a habitat may affect wild species, leading to differences in their distribution.

Question 21

How to reduce carbon footprints (CO2 emissions):

Answer 21

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, so this will reduce methane emissions.

Governments could tax companies or individuals based on the amount of greenhouse gases they emit - e.g taxing cars based on the amount of CO2 they emit over a set of distance could mean that people choose to buy ones that are more fuel-efficient and so less polluting.

Question 22

Reasons why actions to reduce carbon footprints may be limited:

Answer 22

1. It’s easy enough saying that we should cut emissions, but actually doing it is harder.
2. There’s still a lot of work to be done on alternative technologies that result in lower CO2 emissions.
3. A lot of governments are also worried that making these changes will impact on the economic growth of communities - which could be bad for people’s wellbeing. This’ particularly important important for countries that’re still developing.
4. Because not everyone is on board, it’s hard to make 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.
5. Individuals in developed countries need to make changes to their lifestyles. But it might be hard to get people to make changes if they don’t want to and if there isn’t enough education provided about why the changes are necessary and how to make them.