Flashcards in Module 2 Deck (28):
1
What are the proportions of gases in the atmosphere today?
Nitrogen - 80%
Oxygen - 20%
Carbon dioxide, water vapour and methane - small proportions
2
Why has oxygen increased in the atmosphere?
Photosynthesis, plants release oxygen and reduce the amount of carbon dioxide
3
How has the level of nitrogen increased in the atmosphere?
Nitrogen is very inreactive so doesn't react with substances and volcanoes produced nitrogen
4
Name 3 processes that reduce carbon dioxide
Large amounts dissolved in oceans
Locked away in fossil fuels
Locked inside limestone
5
What are the greenhouse gases?
Water vapour, carbon dioxide and methane
6
What do greenhouse gases do?
They maintain temperature on earth high enough to support life
7
What do greenhouse gases do?
They allow short wavelength radiation to pass through the atmosphere to the earth's surface but absorb the long wavelength radiation from the earth causing the an increase in temperature
8
What human activities increase the amount of greenhouse gases?
Carbon dioxide
- deforestation
- combustion of fossil fuels
Methane
- animal farming
- decomposition of landfills
9
What are the potential effects of global climate change?
Sea levels will rise which cause flooding and coastal erosion
More frequent severe storms
Changes the amount of distribution of rain
Temperature and water stress for humans and dwildlife
Changes to distribution of wildlife species
Changes in food producing capacity of some regions
10
What gases are released into the atmosphere when a fuel is burned?
Carbon dioxide, water vapour, carbon monoxide, soldier dioxide and oxides of nitrogen
11
What is acid rain?
Rain with a pH of 5.6 or lower its caused by pollutants sulcus dioxide and nitric oxides
12
Why is carbon monoxide not easily detected?
It is a colourless and odourless toxic gas, it combines with haemoglobin in the blood reducing he capacity to carry oxygen
13
What are particulates?
They cause global dimming, reducing the sunlight that reaches the earth's surface they cause health problems such as damage to the lungs
14
What is the carbon footbprint?
The total amount of carbon dioxide and other greenhouse gases emitted over the life cycle of a product, service or event
15
What can you do to reduce your carbon footprint?
Alternative energy supplies
Energy conservation
Carbon capture and storage
Carbon taxes and licenses
Carbon off setting including tree planting
Carbon neutrality- zero net release
16
What are the problems of reducing carbon footprint?
Lack of public information and education
Lifestyle changes
Economic considerations
Incomplete international co operation
Scientific disagreement over cause and consequences of global climate changes
17
What is an exothermic reaction?
They transfer energy to the surroundings so the temperature of surroundings increase
E.g. Hand warmers
18
What is an endothermic reaction?
Is one that takes in energy from surroundings so the temperature surroundings decreases
E.g. Ice packs
19
What is bendomex?
Breaking bonds is ending
Making bonds is exo
20
What is activation energy?
The minumum amount of energy needed for a chemical reaction to take place
21
What are cells?
Cells contain chemicals which react to produce electricity
22
How can a simple cell be made?
By connecting 2 different metals in contact with an electrolyte
23
What are batteries?
Two or more cells connected together in series to provide a greater voltage
24
Name 3 types of cells
Rechargeable cells
Non rechargeable cells
Fuel cells
25
What is a cathode?
Negative electrode, hydrogen is supplied as fuel
26
What is an anode?
Positive electrode , oxygen if supplied to electrode
27
Advantages of hydrogen fuel cells
No pollutants produced
Can be a range of sizes
Don't have to be electrically charged
28