Chemistry Of The Atmosphere

Question 1

Roughly how old is the Earth?

Answer 1

4.6 billion years old

Question 2

Percentage of Nitrogen in today’s atmosphere

Answer 2

Around 80%

Question 3

Percentage of Oxygen in today’s atmosphere

Answer 3

Around 20%

Question 4

Other gases in the the atmosphere and their percentage

Answer 4

• Carbon Dioxide
• Water Vapour
• Argon
• Noble Gases
• Less than 1%

Question 5

Early Atmosphere Formation
(The First 1 Billion Years)

Answer 5

• Early atmosphere was mostly CO2 (similar to Mars and Venus’ atmosphere today)
• Volcano eruptions released water vapour, nitrogen and small amounts of methane and ammonia into the atmosphere
• Water vapour condensed, forming oceans and CO2 dissolved in it to form carbonate precipitate

Question 6

How did Oxygen in the atmosphere increase?
(2.7 Billion Years Ago)

Answer 6

• Algae and plants evolved and
  photosynthesised
• They took in CO2, releasing O2
• CO2 levels decreased, O2 levels increased allowing complex life forms (animals) to
  evolve
• Plants and algae died and got trapped in sediment layers
• Sediment eventually compressed (due to pressure) and became sedimentary rock, oil and gas
• This trapped carbon in the layers

Question 7

How did crude oil and natural gas form?

Answer 7

From dead plankton

Question 8

How did coal (sedimentary rock) form?

Answer 8

From dead plant matter

Question 9

How did limestone (sedimentary rock) form?

Answer 9

From the calcium carbonate precipitate formed when the CO2 dissolved in the oceans

Question 10

Greenhouse Gases

Answer 10

Maintain temperatures on Earth high enough to support life on Earth

Question 11

What are the Greenhouse Gases?

Answer 11

• Water Vapour
• Methane
• CO2

Question 12

The Greenhouse Effect

Answer 12

• Sun’s energy is radiated in short wavelengths
• Passes through the atmosphere hitting the Earth’s surface
• Some is absorbed, some is reemitted in long wavelengths
• Most of the remission hits gas particles that reemit and absorb the energy again and again
• This keeps the Earth warm as the energy doesn’t leave the atmosphere

Question 13

The Problem of the Greenhouse Effect

Answer 13

• Human activities increase the concentration of CO2 and methane in the atmosphere
• Greenhouse effect increases, causing global warming

Question 14

2 Main Reasons for Global Warming

Answer 14

• Increase in burning fossil fuels that release carbon
• Deforestation so less trees for photosynthesis to take in CO2

Question 15

Climate Change

Answer 15

• Effects of global warming
• Leads to the alteration of long term weather patterns on the planet

Question 16

Why are the consequences of global warming harder to know?

Answer 16

• Lots of variable to take into account for climate change
• Scientists can’t make models or clear predictions of what will happen next

Question 17

Examples of Climate Change

Answer 17

• Sea Level Rises (ice caps melt, temperature increase expands water increasing volume)
• Rare weather events (droughts, hurricanes, floods) become more frequent and severe
• Habitats will change and animals in those habitats won’t adapt quickly enough, endangering them

Question 18

Carbon Footprint

Answer 18

The total amount of CO2 and other greenhouse gases emitted over the full life cycle of a product, a service or an event

Question 19

Benefits of measuring Carbon Footprints

Answer 19

• Have an idea of how environmentally damaging something is
• Able to decide whether something is worth the cost
• Able to identify the activities that produce the most carbon emissions

Question 20

Problem with measuring Carbon Footprints

Answer 20

Can be difficult as many factors have to be taken into account:
- How materials were sourced
- Transportation of materials
- Manufacturing Process
- Lifetime power usage
- Disposal

Question 21

Ways to decrease Carbon Footprint

Answer 21

• Use renewable energy sources
• Use more efficient manufacturing processes
• Governments can introduce new laws and taxes for carbon emitting companies
• Carbon Capture Technology
• Recycling

Question 22

Why is reducing emission so difficult?

Answer 22

• Renewable energy is more expensive than fossil fuels
• Entire economies are based in fossil fuels
• More expensive lifestyle for individuals

Question 23

Incomplete Combustion of Hydrocarbons

Answer 23

Hydrocarbon + Oxygen –> Carbon monoxide + Particulates (Soot)

Question 24

Problems with Particulates

Answer 24

• Cause respiratory problems
• Create smog which reflects sunlight, causing global dimming

Question 25

Problems with Carbon Monoxide (CO)

Answer 25

• CO binds to haemoglobin so less oxygen is carried round the body
• CO is colourless and odourless so is hard to detect

Question 26

Production of Sulfur Dioxide and Nitrogen Oxides

Answer 26

• SO2 is produced when impure hydrocarbons are burnt and the sulfur in them is oxidised
• Nitrogen oxides are produced when nitrogen reacts with oxygen (from air)

Question 27

Problems with Sulfur Dioxide and Nitrogen Oxides

Answer 27

• Cause respiratory problems
• React with water in the clouds to produce acid rain that damages buildings and plants