C11 The Earths Atmosphere

Question 1

How long has the proportions of gases in the atmosphere been about the same as today

Answer 1

200 million years

Question 2

What percentage of the Earth’s atmosphere is made up of Nitrogen

Answer 2

About 4/5 (80%)

Question 3

What percentage of the Earth’s atmosphere is made up by Oxygen

Answer 3

About 1/5 (20%)

Question 4

What are other small proportions of gases in Earth’s atmosphere

Answer 4

Carbon dioxide, water vapour, noble gases

Question 5

Why aren’t we sure on what earth’s early atmosphere was like

Answer 5

It was billions of years ago so nobody was present to see and document it.

Question 6

What happened during the first billion years of Earth’s existence

Answer 6

Intense volcanic explosions released the gases that formed the early atmosphere-mainly-CO2 and H2O

Question 7

What was Eath’s atmosphere similar to today

Answer 7

The atmosphere of mars and venus.

Question 8

How eere oceans formed

Answer 8

Volcanoes released water vapour which condensed and formed oceans

Question 9

What happened when oceans were formed

Answer 9

CO2 dissolved in the water, and the carbonates precipitated out and produced sediments. This reduced the amount of CO2 in the atmosphere

Question 10

What gas did volcanoes produce which gradually built up in the atmosphere

Answer 10

Nitrogen.

Question 11

Step by step of the Earth’s atmosphere being created

Answer 11

Atmosphere—oceans—sediments+shells

Question 12

Five changes to the atmosphere after the early atmosphere

Answer 12

-Oxygen increased (supported life)
-Carbon dioxide decreased
-Methane decreased
-Ammonia decreased
-Nitrogen increased

Question 13

How did oxygen get increased

Answer 13

Algae and plants produced the O2 that is now in the atmosphere via photosynthesis. The level of oxygen gradually increased over a billion year time frame to a level which enabled animals to evolve.

Question 14

When did algae first produce oxygen

Answer 14

2.7 billion years ago

Question 16

How was limestone formed

Answer 16

-Carbon dioxide dissolved in oceans to for carbonate ions.
-These ions were used by marine organisms to build shells/skeletons out of calcium carbonate
-Upon death, the shells sank
-They were then compressed/buried over millions of years to form sedimentary rock such as limestone.

Question 17

How was coal formed

Answer 17

-Plants and trees used CO2 during photosynthesis to build their tissue
-Plants and trees died in swamps and decayed in the absence of oxygen
-They were compressed over millions of years to form coal.

Question 18

How were crude oil and natural gas produced

Answer 18

-Crude oil and natural gas both formed from an ancient biomass (plankton) buried in mud.
-The remains of the plankton were covered by more sediment.
-They were compressed over millions of years to form crude oil and natural gas.

Question 19

Why has the amount has CO2 stayed the same and for how long

Answer 19

Stayed the same for 200 million years due to the carbon cycle.

Question 20

How did methane decrease

Answer 20

Methane reacted with the O2 that was being produced by photosynthesis

Question 21

How did ammonia decrease

Answer 21

Ammonia reacted with the O2 that was being produced by photosynthesis

Question 22

How did notrogen increase

Answer 22

Nitrogen gas is very unreactive so it was able to build up in the atmosphere.

Question 23

What do greenhouse gases do

Answer 23

They maintain temperatures on Earth high enough to support life.

Question 24

What are the main greenhouse gases

Answer 24

Water vapour, carbon dioxide, methane.

Question 25

How do greenhouses work

Answer 25

They allow short wavelength radiation from the sun through but the glass absorbs the long wavelength radiation emitted from inside the greenhouse. This keeps the plants inside warm.

Question 26

What is the greenhouse effect

Answer 26

1. The sun emits short-wavelength radiation which warms the earth 2. The Earth loses heat by emitting long wavelength radiation. 3. Greenhouse gases absorb some of the long wavelength radiation. 4. They re-radiate this thermal radiation in all directions including back to earth this warms the atmosphere.

Question 27

Benefits and drawback of greenhouse gases/effect

Answer 27

Without the greenhouse effect, Earth would be too cold to support life. However, humans are increasing the levels of greenhouse gases in the atmosphere which is warming the earth too much.

Question 28

Human activities which emit carbon dioxide

Answer 28

Burning fossil fuels and deforestation (reduces the CO2 absorbed by trees for photosynthesis).

Question 29

Human activities which emit methane

Answer 29

Cattle and landfill sites (the decay of waste in landfill by microorganisms produces methane).

Question 30

What is global warming

Answer 30

The temperature of Earth's atmosphere increasing. It will cause extreme weather events.

Question 31

What is peer-reviewed evidence

Answer 31

-Other scientists checking the evidence before it is published and scientists collecting and analysing data.

Question 32

How do scientists model the effect of climate change

Answer 32

1. They create a hypothesis 2. They collect data and write a computer program=model 3. Model "predicts" future

Question 33

Effects of global climate change

Answer 33

-Polar ice caps melt -Sea levels rise -Flooding of land -More extreme weather events occur more often -Changes in rainfall. -Animals go extinct.

Question 34

What is the carbon footprint

Answer 34

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

Question 35

How can carbon footprint be reduced

Answer 35

Reducing emissions of CO2 and CH4

Question 36

How can methane emissions be reduced

Answer 36

-Eating less beef -Sending less waste to landfill

Question 37

How can Carbon dioxide emission be reduced

Answer 37

-Charging more tax on polluting vehicles -Using biofuels -Capturing CO2 produced in power stations and storing it in rocks.

Question 38

Carbon Capturing and Storage (CCS) advantages and disadvantages

Answer 38

Advantage- Reduces the CO2 levels in the atmosphere Disadvantage- Expensive technology

Question 39

What do most fuels contain

Answer 39

Carbon and/or hydrogen, and may also contain some sulfur.

Question 40

How is carbon dioxide produced and what are its effects.

Answer 40

Produced by complete combustion of hydrocarbon fuels and it enhances the greenhouse effect and causes global warming.

Question 41

How is carbon monoxide produced and what are its effects

Answer 41

Produced by incomplete combustion of hydrocarbon fuels. It is a toxic gas which is colourless and odourless. It binds to haemoglobin in the red blood cells in place of oxygen.

Question 42

How is sulfur dioxide produced and what are its effects

Answer 42

The sulfur reacts with oxygen during combustion to produce sulfur dioxide. It causes respiratory problems and causes acid rain.

Question 43

How are nitrogen oxides produced and what are its effects

Answer 43

The high temperature of the engine causes the nitrogen in the air to react with the oxygen in the air. It causes respiratory problems and acid rain.

Question 44

How are solid particulates (unburned fuel/soot) produced and what are its effects

Answer 44

If diesel doesn't burn completely, tiny solid particles of carbon (soot) and unburnt fuel are produced-called particulates. They cause lung damage and cause global warming