The Earth's Atmosphere

Question 1

State what happened in the first phase of the Earth’s evolution

Answer 1

Volcanoes erupted, releasing mainly carbon dioxide but also nitrogen, water vapour, methane and ammonia.

Question 2

State what happened in the second phase of the Earth’s evolution

Answer 2

Water vapour in the air condensed forming the Oceans and lots of carbon dioxide dissolved in those oceans, that then turned into sediments on the seabed. Green plants and algae started to evolve and began to photosynthesise the CO2. Then marine animals evolved and their fossils contained carbonates and stored the carbon from the atmosphere away.

Question 3

State what happened in the third phase of the Earth’s evolution

Answer 3

Green plants and algae began to produce oxygen via photosynthesis and the algae began to evolve. This caused oxygen levels to build up for more complex life. Finally, about 200 million years ago the atmosphere reached a similar composition to what it is now

Question 4

State the Composition of gases in the modern - day atmosphere

Answer 4

80% Nitrogen, 20% Oxygen and small amounts of other gases e.g. CO2 and other noble gases and water vapour.

Question 5

Explain the Greenhouse effect

Answer 5

1. Shortwave radiation from the sun enters the atmosphere and hits earth
2. It is reflected as long-wave radiation and some escapes the atmosphere HOWEVER, greenhouse gases trap some of the long wave radiation which then continues to heat the Earth.

Question 6

State some causes of Climate Change

Answer 6

Deforestation, Burning Fossil Fuels, Agriculture, Creating waste (Landfills)

Question 7

State the consequences of Climate Change

Answer 7

1. Ice caps melting causing a rise in sea levels
2. Changes in rainfall patterns
3. Frequency and severity of storms will increase
4. Changes in temperature and water.

Question 8

What is incomplete combustion?

Answer 8

Where there is not enough oxygen in a reaction so not all fuel is burned so carbon monoxide is released as well as other harmful particulates.

Question 9

What can particulates harm?

Answer 9

They can get stuck in the lungs and cause damage. OR. They can reflect sunlight back into space meaning less light reaches the Earth causing Global Dimming.

Question 10

What harm does carbon monoxide cause?

Answer 10

It can stop haemaglobin from binding to oxygen in your blood by binding to the haemaglobin instead.

Question 11

What problems do Sulfur dioxide and Oxides of Nitrogen cause?

Answer 11

1. They mix with clouds forming dilute sulfuric acid, which then falls as acid rain.
2. Acid rain kills plants and damages buildings, and also corrodes metals.
3. They can also cause respiratory problems.