4.9.1

Question 1

What is the percentage of nitrogen?

Answer 1

80%

Question 2

What is the percentage of oxygen in the atmosphere

Answer 2

20%

Question 3

What other gases in the atmosphere

Answer 3

Carbon dioxide, water vapour and noble gases.

Question 4

What is the original theory for the composition of the atmosphere?

Answer 4

Volcanic activity released gases that formed the early atmosphere
Water vapour condensed to form oceans
Mainly carbon dioxide and little to no oxygen gas.
Nitrogen was formed from volcanic eruptions which built up ammonia

Question 5

How did oxygen levels increase?

Answer 5

Algae and plants photosynthesise which produces oxygen.

Question 6

How has carbon dioxide levels decrease?

Answer 6

Algae and plants through photosynthesis and act as carbon sinks
Carbon dioxide also got trapped in the form of sedimentary rocks and fossil fuels that contain carbon
Dissolved in oceans

Question 7

Green house gases:

Answer 7

Carbon dioxide, methane, water vapour

Question 8

Describe the green house effect:

Answer 8

Short wavelength Radiation from the sun passes through the earths atmosphere.
Earths surface re radiates it as long wavelength radiation
Long wavelength radiation is absorbed by green house gases in the atmosphere, leading to the greenhouse effect and global warming.

Question 9

How have human activities contributed to an increase in greenhouse gases:

Answer 9

Human activities increase carbon dioxide and methane
Carbon dioxide:
Cars, electricity
Methane:
Raising livestock, decay of organic waste in landfill sites.

Question 10

What do scientists believe based on peer reviewed evidence?

Answer 10

Human activities will cause the temperature of the earths atmosphere to increase at the surface and that this will result in global climate change

Question 11

What are the facts of climate change?

Answer 11

Extinction of species, raising sea levels and melting polar ice caps, migration, decrease in crop yields for all major world crops.

Question 12

What is carbon footprint and how can it be reduced?

Answer 12

Amount of carbon dioxide and other greenhouse gases emitted over the full lifecycle of a product service or event.
It can be redid by reducing emissions of carbon dioxide and methane by using less electricity (solar power), and planting more trees.

Question 13

What process is a major source form atmospheric pollution

Answer 13

Combustion of fuels - most fuels contain carbon or hydrogen, and sulphur

Question 14

What gases are released when fuels burn?

Answer 14

Carbon dioxide, water vapour, carbon particulates, carbon monoxide, nitrous oxides

Question 15

Equation for combustion?

Answer 15

Fuel + oxygen -> carbon dioxide + water

Question 16

Properties and effects of carbon monoxide:

Answer 16

Toxic gas, colourless and odourless which means its hard to detect. It binds to the haemoglobin in the blood and stops the blood from transporting oxygen.

Question 17

Properties and effects of sulphur dioxide and nitrous oxides.

Answer 17

Cause acid rain and respiratory problems (from cars)

Question 18

Properties and effects of soot?

Answer 18

Causes global dimming and human health problems