C9 - Chemistry of the Atmosphere

Question 1

How did the early atmosphere form?

Answer 1

Volcanoes erupting gases.

Question 2

What was the original atmosphere made up billions of years ago?

Answer 2

Mainly carbon dioxide, volcanoes produced:

Nitrogen, water vapour, little methane & ammonia.

Question 3

How were oceans formed?

Answer 3

The water vapour in the atmosphere condensed.

Question 4

What happened to carbon dioxide when oceans formed?

Answer 4

It dissolved and formed carbonate precipitates that formed sediments on the sea bed.

Question 5

How did carbon dioxide levels decrease?

Answer 5

Green plants and algae used it in photosynthesis.

Question 6

How are fossil fuels formed?

Answer 6

1. Plants, animals, plankton die.
2. These are buried by layers of sediment.
3. It becomes compressed and forms sedimentary rock.

Question 7

How did oxygen levels increase?

Answer 7

Photosynthesis by green plants and algae.

Question 8

When did our modern atmosphere start?

Answer 8

About 200 million years ago the atmosphere was similar to how it is today. (80% nitrogen, 20% oxygen, less than 1% other gases).

Question 9

What did our modern atmosphere cause?

Answer 9

More complex life could develop/evolve e.g animals

Question 10

How do greenhouse gases play a role in climate change?

Answer 10

Gases absorb longwave radiation then re-radiate it in all directions - including to Earth.

Question 11

Describe the greenhouse effect.

Answer 11

Longwave radiation is thermal radiation so heats the Earth when it is re-radiated from gases in the atmosphere.

Question 12

Give 2 human activities that contribute to greenhouse gases in the atmosphere.

Answer 12

Any of:

1. Deforestation - less CO2 being photosynthesised.
2. Burning fossil fuels - releases carbon as dioxide.
3. Agriculture - methane produced from digestive system.
4. Creating waste - C02 and methane produced.

Question 13

Give 2 consequences of climate change.

Answer 13

Any of:

1. Polar ice caps melting = flooding, sea levels rise, coastal erosion
2. Change in rainfall pattern - difficult for food produce
3. Increased frequency and severity of storms
4. Change in species distribution.

Question 14

Why is the Earth’s climate hard to understand?

Answer 14

It is so complex with so many variables.

Question 15

Define carbon footprint.

Answer 15

Total greenhouse gases released over a life cycle of a product.

Question 16

Why is carbon footprint hard to measure?

Answer 16

Many factors should be considered so it’s almost impossible to measure. This means it’s a rough estimate.

Question 17

Give the 4 stages considered in carbon footprint.

Answer 17

1. Sourcing the materials
2. Making the product
3. Using the product
4. Disposal

Question 18

Give 3 ways to reduce carbon footprint.

Answer 18

1. Use renewable/nuclear energy sources
2. Use efficient methods to conserve energy and reduce waste
3. Create a tax or law based on emissions.

Question 19

What are the cons of attempting to reducing carbon footprint? (3)

Answer 19

1. Can harm the progress of developing countries and economies
2. Hard to make everyone agree
3. People need to accept it as part of their lifestyle

Question 20

What does complete combustion release into the atmosphere?

Answer 20

Carbon dioxide and water vapour.

Question 21

What does incomplete combustion release into the atmosphere?

Answer 21

Particles of soot and unburnt fuel produce carbon monoxide and dioxide during incomplete combustion.

Question 22

What harm can particulates cause? (2)

Answer 22

1. Respiratory problems - stuck in the lungs

2. Global dimming - produces clouds that reflect the sunlight back into space, this means less sunlight to Earth.

Question 23

Give 2 dangers of carbon monoxide.

Answer 23

1. Binds to haemoglobin instead of oxygen. This can cause fainting, a coma or death.
2. It’s hard to detect as it’s colourless and odourless

Question 24

What happens when sulfur or nitrogen combust?

Answer 24

They become sulfur dioxide/nitrogen oxide.

Question 25

What can sulfur dioxide or nitrogen oxide cause?

Answer 25

Acid rain

Question 26

Give 2 risks of acid rain.

Answer 26

Any of:

1. Plants die
2. Buildings and statues corrode
3. respiratory problems