Chemistry of the Atmosphere

Question 1

For how many years has the proportion of atmospheric gases been much the same as today?

Answer 1

200 million

Question 2

What proportion of the atmosphere is nitrogen

Answer 2

≈ 80%

Question 3

What proportion of the atmosphere is oxygen?

Answer 3

≈ 20%

Question 4

What proportion of the atmosphere is made from gases other than nitrogen and oxygen?

Answer 4

A small proportion

Question 5

What gases make up the atmosphere other than nitrogen and oxygen?

Answer 5

Various others, including carbon dioxide, water vapour and noble gases.

Question 6

Theories about what was in the Earth’s early atmosphere and how the atmosphere was formed have…

Answer 6

…changed and developed over time.

Question 7

Why is evidence for the early atmosphere limited?

Answer 7

Because of the time scale of 4.6 billion years.

Question 8

What is step one in the theory of the Earth’s Early atmosphere?

Answer 8

There was intense volcanic activity in the first billion years of the Earth’s existence.

Volcanoes released the gases which formed the early atmosphere, and water vapour.

Question 9

What is the Earth’s atmosphere thought to have been like in the 1st billion years of its existence?

Answer 9

The atmospheres of Mars and Venus today.

Question 10

What gases did intense volcanic activity release?

Answer 10

Carbon dioxide with little or no oxygen gas.

Question 11

What is step two to the theory of Earth’s early atmosphere?

Answer 11

Earth cooled, so the water vapor condensed. This formed our oceans.

Question 12

What is step three to the theory of Earth’s early atmosphere?

Answer 12

When the oceans formed, carbon dioxide dissolved in the water, forming carbon precipitates and sediments.

This reduced the amount of carbon dioxide in the atmosphere.

Question 13

What produces the oxygen now in the atmosphere?

Answer 13

Green plants and algae.

Question 14

How do green plants and algae produce oxygen?

Answer 14

Photosynthesis.

Question 15

What is the photosynthesis word equation?

Answer 15

carbon dioxide + water to glucose + oxygen

Question 16

When did algae first produce oxygen?

Answer 16

~ 2.7 billion yrs ago.

Question 17

How did the percentage of oxygen in the atmosphere increase?

Answer 17

Oxygen appeared in the atmosphere soon after algae first produced it.

Over the next billion years, plants evolved and the percentage of oxygen gradually increased to a level that allowed animals to evolve.

Question 18

How did levels of carbon dioxide decrease?

Answer 18

Algae and plants decreased the percentage of carbon dioxide in the atmosphere by photosynthesis.

Carbon dioxide was also decreased by the formation of sedimentary rock and fossil fuels that contain carbon.

Question 19

Describe and explain the formation of deposits of limestone.

Answer 19

Limestone is a sedimentary rock made mostly of calcium carbonate deposits (from the shells and skeletons of marine organisms) that have been compressed over millions of years.

Question 20

Describe and explain the formation of deposits of coal.

Answer 20

Coal is a sedimentary rock made from thick plant deposits that have been compressed over millions of years.

Question 21

Describe and explain the formation of deposits of crude oil.

Answer 21

Reservoirs of crude oil are formed under the sea bed when deposits of plankton are trapped in rocks.

Question 22

Describe and explain the formation of deposits of natural gas.

Answer 22

Reservoirs of natural gas are formed under the sea bed when deposits of plankton are trapped in rocks.

Question 23

What is trapped working sedimentary rock?

Answer 23

Carbon, which helps to keep carbon dioxide levels in the atmosphere reduced.

Question 24

What is sedimentary rock?

Answer 24

A type of rock formed from compressed layers of minerals and organic particles such as sand, mud, and shells.

Question 25

What is the atmosphere?

Answer 25

A layer of gases surrounding the Earth that is held in place by gravity.

Question 26

What is the difference between climate change and global warming?

Answer 26

Global warming refers to the overall increase in Earth’s temperature, whereas climate change is a consequence of global warming, and refers to the effects on the climate, like large-scale shifts in weather patterns.

Question 27

What could an increase in the volume of ocean water lead to?

Answer 27

Seasonal flooding, or the submersion of low- lying areas.

Question 28

Why are greenhouse gases in the atmosphere a good thing?

Answer 28

They maintain temperatures on Earth high enough to support life.

Question 29

Name some greenhouse gases.

Answer 29

Carbon dioxide Methane Water vapour

Question 30

Describe the greenhouse effect and how it effects global temperatures.

Answer 30

The sun gives out short wave radiation which is reflected back by the Earth as long wave/ thermal radiation. The thermal radiation is absorbed by greenhouse gases in the atmosphere. Greenhouse gases give out the thermal radiation in all directions including back towards the Earth, causing the temperature to rise. (warmer and more stable).

Question 31

Which greenhouse gases do human activities increase?

Answer 31

Carbon dioxide Methane

Question 32

Name two human activities that increase the amount of carbon dioxide in the atmosphere.

Answer 32

Deforestation, which reduces the amount of CO2 removed from the atmosphere by photosynthesis. Burning fossil fuels, which releases the carbon ‘locked up’ in them.

Question 33

Name two human activities that increase the amount of methane in the atmosphere

Answer 33

Agriculture: farm animals produce methane during digestion. An increase in landfill sites and waste from agriculture means more methane (and CO2!) released by decomposition.

Question 34

How do we know evidence for climate change is reliable?

Answer 34

It had been peer reviewed.

Question 35

Why doesn’t everyone trust the evidence for climate change? .

Answer 35

The earth’s climate is too complex to fully understand and model.

Question 36

The earth’s climate is too complex to fully understand and model. What has this led to?

Answer 36

Simplified models, speculation and opinions presented in the media that may be based on only parts of the evidence or biased.

Question 37

What is the scientific consensus about climate change?

Answer 37

-Hunan activities will cause the temperature if the Earth’s atmosphere to increase at the surface -This will result in global climate change

Question 38

Describe uncertainties in the scientific evidence base.

Answer 38

Reports in the media are NOT peer reviewed. So, data may be presented in a way that is oversimplified/inaccurate. This can leave it open to misinterpretation. Bias e.g giving data that supports an idea but none against it.

Question 39

What is a major cause of climate change?

Answer 39

An increase in average global temperature.

Question 40

Briefly describe four potential effects of global climate change.

Answer 40

1) Polar ice caps melting = rise in sl = increased flooding and coastal erosion 2) Changes in rainfall patterns = drought or flooding = impacts food security 3) Frequency and severity of storms might increase 3) Changes in temperature affects migration patterns and hence the distribution of species.

Question 41

You need to…

Answer 41

…discuss the scale, risk, and environmental implications of global climate change. x

Question 42

What is the carbon footprint?

Answer 42

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

Question 43

How can the carbon footprint be reduced?

Answer 43

By reducing emissions of carbon dioxide and methane.

Question 44

Describe actions to reduce emissions of carbon dioxide and methane.

Answer 44

-Using renewable energy sources -Governments can put a cap on the amount of greenhouse gases that a business can emit and issue licenses for set amounts of emissions up to this point -Governments can impose taxes in companies according to the amount of gasses they emit to encourage them to cut down on emissions. -Carbon Capture and Storage -Recycling rather than disposal in landfill -Creation siring fewer/more sustainable raw materials

Question 45

Give reasons why it’s difficult to measure the carbon footprint.

Answer 45

There arre many factors to consider i.e the carbon emitted at each stage of an object lifetime including sourcing all the parts. However rough calculations do help to see what the worst emitters are to avoid them in the future.

Question 46

Why is making reductions in the emissions of carbon dioxide and methane difficult?

Answer 46

-Alternative technologies not fully developed -Governments worry about the impact in the economy, particularly for developing countries -It’s hard to make international agreements bc countries don’t want to sacrifice their economic development if others won’t do the same -Individuals must be willing and educated enough to change their lifestyles

Question 47

Give 4 factors you’d need to consider when calculating the carbon footprint of a car

Answer 47

-How all the raw materials were sourced -The manufacturing process -The total amount of fuel it used over its lifetime - How it’s disposed of

Question 48

CCS

Answer 48

A technology that allows us to trap carbon and store it deep underground.

Question 49

What is a major source of atmospheric pollutants.

Answer 49

The combustion of fuels/hydrocarbons.

Question 50

What gases might be released into the atmosphere when a fuel is burned?

Answer 50

Carbon dioxide, water vapor (complete combustion) Carbon monoxide, particulates (incomplete combustion) Sulfur dioxide, Oxides of nitrogen.

Question 51

What are particulates?

Answer 51

Solid particles of carbon/ ‘soot’.

Question 52

What is the problem with carbon particulates?

Answer 52

-Respiratory problems if particulates get stuck in our lungs and cause damage. -Global dimming

Question 53

What is global dimming?

Answer 53

Where smog reflects sunlight into space so less reaches the Earth.

Question 54

What do most fuels contain?

Answer 54

-Carbon and/or hydrogen -They may also contain some sulfur

Question 55

What forms particulates?

Answer 55

Solid particles and unburned hydrocarbons released when fuels are burned.

Question 56

Describe how sulfur dioxide is produced through the burning of fuels.

Answer 56

Impurities (e.g. sulfur) are oxidised to form e.g. sulfur dioxide.

Question 57

Describe how oxides of nitrogen are produced by burning fuels.

Answer 57

Nitrogen reacts with oxygen to form nitrous oxides at really high temperatures.(e.g in the combustion chamber of a car)

Question 58

Why is it important to communicate the results of scientific research to a wide range of audiences?

Answer 58

-Results might show the public should change their habits -Results might provide ideas that can be developed into new technology -E.g. info on fullerenes needs to be relayed to doctors so they can make informed decisions about using fullerene drug delivery systems in treatment

Question 59

What is the problem with sulfur monoxide?

Answer 59

-If breathed in, it diffuses into our bloodstream and binds to haemoglobin -This reduces the amount of oxygen that haemoglobin can carry -So, less oxygen is transported to the tissues, which can cause symptoms such as fainting, coma and death

Question 60

What is the problem with sulfur dioxide AND oxides of nitrogen?

Answer 60

-Respiratory problems if the gases gets into our lungs and cause damage -Acid rain

Question 61

How is acid rain formed?

Answer 61

Sulfur dioxide OR oxides of nitrogen mix with clouds The gases dissolve to form dilute sulfuric or dilute nitric acid This falls as acid rain

Question 62

What are the adverse effects of acid rain?

Answer 62

-It damages certain buildings and statues -It corrodes metals -It damages plants directly by falling on leaves -It makes the soil more acidic, which harms plants indirectly

Question 63

How can we test for sulfur impurities in fuel?

Answer 63

Bubble the gases from combustion through a solution containing universal indicator. If the solution turns red, this indicates the presence of sulfuric acid (formed from SO₂ which would have dissolved).

Question 64

What makes carbon monoxide hard to detect?

Answer 64

It's both colourless and odourless.