Chemistry of the Atmosphere (Unit 9)

Question 1

What is the rough composition of the Earth’s atmosphere today?

Answer 1

80% nitrogen, 20% oxygen, 0.04% carbon dioxide; small amount of other gases e.g. xenon, hydrogen, WATER VAPOUR

Question 2

What are the greenhouse gases?

Answer 2

Water vapour, Carbon Dioxide, Methane

Question 3

What was the original composition of the early Earth?

Answer 3

We cannot be sure, but judging from Venus and Mars’ atmosphere, it would have been mainly CARBON DIOXIDE, NITROGEN, and small amounts of METHANE, AMMONIA

Question 4

How was coal, crude oil, and natural gas formed?

Answer 4

Coal- dead plants in swamps

Crude oil AND natural gas- dead plankton/sea creatures

Question 5

How did Earth’s atmosphere change from early one to now (according to one theory)?

Answer 5

1) In the beginning, there were many volcanoes. They released a lot of CO2, water vapour, and nitrogen.
2) This meant it was really hot.
3) The water vapour condensed to form oceans, and tectonic activity created landforms over volcanoes on the crust
4) The first bacteria (cyanobacteria) and plankton from sea evolved and photosynthesised.
5) Oxygen was thus released and built up over NEXT BILLION YEARS. The nitrogen would have built up over time from volcanic activity.
6) The CO2 absorbed from photosynthesis was stored in animals in ocean; this decayed under heat and pressure and compressed to become fossil fueld on sea bed
7) CO2 also dissolved in oceans. Carbonates were precipitated and compressed on sea bed to form sedimentary rock e.g. limestone.
8) This reduced amount CO2 in atmosphere.

Question 6

What is limestone?

Answer 6

Calcium carbonate

Question 7

When did algae first produce oxygen?

Answer 7

2.7 billion years ago

Question 8

How did gases such as methane and ammonia decrease in the atmosphere?

Answer 8

They reacted with the oxygen in air

Question 9

How come nitrogen could build up over time?

Answer 9

It is unreactive

Question 10

What EM waves does the sun emit?

Answer 10

UV, visible light, infrared

Question 11

Whcih EM wave is associated with heat?

Answer 11

Infrared (radiation)

Question 12

What happens to the EM rays from sun when they reach Earth?

Answer 12

They all pass through the atmosphere

Earth’s surface absorbs/reflects it

Question 13

What happens to the EM rays when Earth absorbs/reflects it?

Answer 13

• When the Earth’s surface reflects the rays, SHORT-WAVELENGTH RADIATION pass through (e.g. UV light)
• When the Earth EITHER reflects OR emits LONG-WAVELENGTH infrared radiation from the surface, it is absorbed by the greenhouse gases

Question 14

How do greenhouse gases warm the atmosphere?

Answer 14

1) Infrared radiation is absorbed
2) The bonds in the G.Gas molecules vibrate MORE
3) This raises their temperature
4) Heat is thus trapped in the atmosphere

Question 15

What are the contributers to increased greenhouse gas emissions?

Answer 15

• Burning fossil fuels
• Deforestation
• Animal farming/Decomposing waste release methane

Question 16

What are examples of decomposing waste?

Answer 16

landfill, swamps, rice field, grazing cattle

Question 17

What are four causes + effects of climate change/global warming?

Answer 17

• Rising sea levels from expanding ocean and melting ice caps
• More frequent and extreme weather events e.g. tsunamis
• More variation and changes in temp.
• More variation in distribution of rainfall

Question 18

How does global warming effect CO2 in atmosphere?

Answer 18

Oceans become less able to absorb CO2 as temp. increases

So thus more CO2 in atmosphere

Question 19

What is the effect of increased greenhouse gas emission?

Answer 19

Global warming

Question 20

Where is the dispute amongst scientists with global warming?

Answer 20

Whether or not it is caused by human activity and has lead to climate change

Question 21

Why are the causes/effects of global warming bad?

Answer 21

1) Flooding + extreme weather events lead to homelessness
2) Varying temp. and rainfall (e.g. droughts) affect food production
3) Changing environment puts stress on ecosystems and leads to extinction
4) Increased coastal erosion
5) Water stress (water shortage near equator)

Question 22

What is the issue of media presenting data about climate change etc.

Answer 22

They’re not subject to peer review and

may be oversimplified, inaccurate or biased.

Question 23

What kind of organisations will manipulate data to do with climate change?

Answer 23

Fossil fuel corporations, companies using renewable resources

Question 24

What is the ‘carbon footprint’?

Answer 24

The amount of CO2 and other greenhouse gases given out over the full life cycle of a product/service/event

Question 25

What constitutes as the ‘life cycle’ of something?

Answer 25

Drilling, making/processing, transporting…

Question 26

What are greenhouse gases?

Answer 26

Gases that absorb infrared radiation

Question 27

What is the greenhouse effect?

Answer 27

Warming of the Earth’s surface due to heat trapped by greenhouse gases

Question 28

What is global warming?

Answer 28

Rise in average temperatures around the world

Question 29

What is climate change?

Answer 29

The IMPACT of GLOBAL WARMING on the sea levels, extreme weather events, rainfall, and ecosystems

Question 30

How do we reduce the carbon footprint of a product/event?

Answer 30

Reduce CO2 emissions

Question 31

How can we reduce CO2 emissions TO THE ATMOSPHERE?

Answer 31

‘Carbon Capture and Storage’
CO2 PRODUCED FROM FOSSIL FUELS IS PUMPED DEEP UNDERGROUND IN ROCKS
‘Plant based diets’
REDUCE DEMAND FOR BEEF (REDUCED BREEDING) AND EAT LOCALLY TO REDUCE TRANSPORT
‘Carbon off-setting’
REDUCING CO2 EMISSIONS IN ONE PLACE TO COMPENSATE FOR CO2 RELEASE ELSEWHERE E.G. WIND FARMS, PLANTING TREES
‘Taxation on fossil fuels’
THIS MAKES IT EXPENSIVE, SO ALTERNATIVES E.G. BIOFUELS ARE LOOKED INTO AND USED

Question 32

What is the problem with these preventative measures?

Answer 32

1) Scientific disagreement
2) Lifestyle changes (people WANT to use more electrical devices/travel more so consume more energy)
3) Incomplete international co-operation to reduce emissions
4) Costs (alternative/preventative measures are more expensive- not ideal for companies or developing countries)

Question 33

What substances are found in fuel?

Answer 33

Hydrogen, Methane, Ethanol, Carbon Disulfide

Question 34

What happens when the fuel substances burn in excess oxygen?

Answer 34

COMPLETE COMBUSTION:
Carbon Dioxide + Water
(if Carbon Disulfide: Carbon Dioxide + Sulfur Dioxide)

Question 35

What if the fuel substances burn in a poor supply of oxygen?

Answer 35

INCOMPLETE COMBUSTION:

Carbon Monoxide + Water (if Carbon Disulfide: Carbon Monoxide + Sulfur Dioxide)

Question 36

Name five pollutants

Answer 36

Unburned hydrocarbons, carbon particulates/soot, nitrous oxides, sulfur dioxide, carbon monoxide

Question 37

How is carbon monoxide harmful?

Answer 37

• It is toxic
• It is colourless and odourless SO HARD TO DETECT
• It starves the body of oxygen

Question 38

How are carbon particulates harmful?

Answer 38

1) They can cause respiratory illnesses.

2) They can cause global dimming.

Question 39

How are sulfur and nitrous oxides harmful?

Answer 39

1) Can cause acid rain
2) It can cause respiratory illnesses
3) It causes breathing problems