The Earth’s Atmosphere

Question 1

Volcanoes

Answer 1

Released CO2, water vapour, nitrogen

Question 2

Water vapour from volcanoes

Answer 2

Condensed and fell as rain

Collected in crust forming oceans

Question 3

Comets

Answer 3

Icy comets could’ve brought water

Question 4

Earth stabilising

Answer 4

CO2 main gas in atmosphere
Methane and ammonia
No oxygen
Once stabilised, life began

Question 5

Evolution due to oxygen in earths early atmosphere

Answer 5

Bacteria and other simple organisms (algae) evolved
Algae photosynthesised = oxygen
More plants evolved
Plants colonised surface of Earth
Animals evolved
Relied on algae for food

Question 6

Skeletons in Earth’s early atmosphere

Answer 6

Skeletons built at bottom of oceans
Layer of sediment on top of them
Buried under pressure depositing formed sedimentary carbonate rocks
Remains of living things heated on Earth’s crust
Formed fossil fuels

Question 7

Coal’s formation

Answer 7

Coal classed as sedimentary rock

Formed from thick deposits of plant material

Question 8

Crude oil and natural gas formation

Answer 8

Formed from remains of plankton deposited in muds
Covered by sediments that became layers of rocks when compressed over millions of years
Found trapped beneath layers of rocks

Question 9

Ammonia and methane

Answer 9

Ammonia and methane was removed by reactions with oxygen, once oxygen had been formed by photosynthesis

Question 10

Consequences of rising sea levels of greenhouse gases

Answer 10

Melting ice caps
Expansion of warmer oceans
Flooding of low-lying land
Increased coastal erosion
Islands disappear
Extreme weather events = more frequent and severe storms
Disruption of rainfall
Food-producing capacity of different regions affected (dry areas)
Monsoons heavier
Changes to distribution of wildlife species
Ecosystems under stress

Question 11

Carbon footprint

Answer 11

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

Question 12

How is electricity made

Answer 12

Burning fossil fuels

Question 13

Solutions of solving our carbon footprint

Answer 13

Carbon capture and storage

World leaders meet to negotiate limits

Question 14

Problems of reducing carbon footprint

Answer 14

Scientific disagreement causes consequences of global climate change
Incomplete targets for reducing greenhouse gases
Poorer countries not included in negotiations
People need information about climate change to make a positive contribution

Question 15

Pollution from fuels

Answer 15

Contain sulfur = acid rain -> kills animals and plants

Sulfur impurities removed from fuel before burnt

Question 16

Incomplete combustion

Answer 16

Instead of all carbon turning into CO2, some CO is formed
Carbon monoxide = toxic gas, colourless and odourless
Red blood cells carry it instead of oxygen poisoning you

Question 17

High temperatures inside engine

Answer 17

Unreactive nitrogen gas

Makes nitrogen oxides = toxic, affect people with asthma

Question 18

Burn hydrocarbons

Answer 18

Diesel engines burn hydrocarbons = bigger molecules than petrol engines
Large molecules do not burn completely
Tiny solid particles containing carbon, hydrocarbons produced

Question 19

Particulates

Answer 19

Produced from burning hydrocarbons
Carried in air to upper atmosphere
Reflect sunlight back
Global dimming
Damage cells in lungs, cause cancer

Question 20

Combustion of fossil fuels (what is formed)

Answer 20

Nitrogen oxides = oxidation at high temp in vehicle engines
Carbon monoxide = incomplete combustion
Particulates = burning diesel
Sulfur dioxide = oxidation of sulfur impurities
Carbon dioxide = complete combustion