Atmsohphere

Question 1

Describe the proportions of gases in the modern atmosphere

Answer 1

• Around 80% of N
• 20% of 02;
• Small quantities of CO,, HO, and noble gases

Question 2

Describe the Earth’s early atmosphere and how it was formed

Answer 2

a) The Earth was hot when it was formed
b) There was significant volcanic activity
c) Gases have been released from these volcanoes
d) These gases included COz, N2, CHA, NHy, H,O

Question 3

How did the amount of oxygen in the atmosphere increase?

Answer 3

Algae and plants produced the atmospheric O, by photosynthesis, which can be represented by the equation: 6 CO,+ 6 H,O -> CgH,2°+ 6 02. As the amount of gradually O, increased, there were more plants that produced more oxygen.

Question 4

How did the amount of carbon dioxide in the atmosphere decrease?

Answer 4

a) Some CO, was dissolved in the oceans, where it reacted with metal ions to form insoluble carbonates, such as CaCO, or was taken in by animals to become a part of skeleton. When animal dies, this becomes a sedimentary rock.
b) Some CO, was used in photosynthesis to make oxygen.

Question 5

What is the greenhouse effect? What are greenhouse gases? Give examples

Answer 5

Greenhouse gases in the atmosphere maintain temperatures on Earth high enough to support life.
They allow short wavelength radiation from the sun to pass through the atmosphere to the Earth’s surface, but absorb the outgoing long wavelength radiation from the Earth causing an increase in temperature.
Water vapour, carbon dioxide, and methane

Question 6

Why is the greenhouse effect necessary for life?

Answer 6

The greenhouse effect is a natural phenomenon. Without it, the Earth would be too cold for life to exist.

Question 7

How have human activities led to an increase in greenhouse gases?

Answer 7

Carbon dioxide - combustion and deforestation
Methane - increased farming and decomposition in landfills

Question 8

What are the potential effects of global climate change?

Answer 8

• sea level rise, which may cause flooding and increased coastal erosion
• more frequent and severe storms
• changes in the amount, timing and distribution of rainfall
• temperature and water stress for humans and wildlife
• changes in the food-producing capacity of some regions
• changes to the distribution of wildlife species

Question 9

What is a carbon footprint?

Answer 9

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

Question 10

What actions can be taken to reduce a carbon footprint?

Answer 10

• increased use of alternative energy supplies
• energy conservation
• carbon capture and storage (where CO2 is trapped in solvents and stored underground)
• carbon taxes and licences
• carbon off-setting including through tree planting
• carbon neutrality - zero net release.

Question 11

What are the problems of reducing the carbon footprint?

Answer 11

• scientific disagreement over causes and consequences of global climate change
• lack of public information and education
• lifestyle changes (people don’t want to give up their cars)
• economic considerations (it will cost money)
• incomplete international cooperation

Question 12

What are the advantages of complete combustion?

Answer 12

• less soot (carbon particulates) is made with complete combustion
• more heat per gram of fuel is released with complete combustion
• poisonous carbon monoxide is not produced with complete combustion

Question 13

How is pollution caused by combustion?

Answer 13

When a fuel burns, the gases released to the atmosphere include carbon dioxide, water (vapour), carbon monoxide, sulphur dioxide and oxides of nitrogen.
Solid particles and unburned hydrocarbons may also be released that form particulates in the atmosphere.

Question 14

What are the issues regarding sulfur dioxide and oxides of nitrogen?

Answer 14

Sulfur dioxide and oxides of nitrogen cause respiratory problems in humans and cause acid rain. Acid rain damages plants and buildings.

Question 15

What problems do particulates cause?

Answer 15

Particulates, such as carbon particles, cause global dimming by reducing the amount of sunlight that reaches the Earth’s surface. Particulates cause health problems for humans because of damage to the lungs.

Question 16

greenhouse effect

Answer 16

Solar radiation from the sun passes through the atmosphere and hits the earth.
Some of this energy is reflected straight back towards space, and some of it is absorbed by the earth and then re-emitted towards space.
Some of the energy makes it all the way to space, but much of it is absorbed by small molecules called greenhouse gases.
These molecules then re-emit the energy and the whole process of absorption and emission happens over and over again.
This trapped energy keeps the atmosphere warmer and more stable than it otherwise would be.

Question 17

difference between global warming and climate change

Answer 17

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

Question 18

difference between climate and weather

Answer 18

Weather refers to short term atmospheric conditions, like whether it’s raining or sunny on a particular day
Climate describes the typical weather conditions in an entire region for a very long time

Question 19

three factors you would you need to take into account when calculating the carbon footprint of a car.

Answer 19

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

Question 20

three general ways we could reduce the carbon footprint of a product.

Answer 20

Create it using fewer, or more sustainable, raw materials
Use a more efficient manufacturing process (e.g. less energy or less waste)
Use renewable energy resources (e.g. wind, solar, or nuclear)
Recycle it, rather than disposing of it in landfill

Question 21

Describe why carbon monoxide is harmful for humans.

Answer 21

When we breathe in carbon monoxide it diffuses into our bloodstream, and binds to our 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 22

three factors you would you need to take into account when calculating the carbon footprint of a car.

Answer 22

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

Question 23

Give three general ways we could reduce the carbon footprint of a product.

Answer 23

Create it using fewer, or more sustainable, raw materials
Use a more efficient manufacturing process (e.g. less energy or less waste)
Use renewable energy resources (e.g. wind, solar, or nuclear)
Recycle it, rather than disposing of it in landfill

Question 24

how is sulfur dioxide formed?

Answer 24

Sulfur is an impurity in some fossil fuels and is oxidised when they’re combusted

Question 25

When burning fossil fuels in an engine, how are nitrogen oxides formed?

Answer 25

Nitrogen from the air is oxidised at the high temperature inside the engine