Earth Flashcards
How much of the atmosphere is oxygen?
21%
How much of the atmosphere is nitrogen?
78%
How much of the atmosphere is argon?
1%
How much of the atmosphere is Co2?
0.03%
How much of the atmosphere is other gasses?
0.17%
What is the greenhouse effect?
The greenhouse effect is the trapping of the heat in the Earths atmosphere by certain gasses
What gasses cause the greenhouse effect?
- carbon dioxide
- methane
- Nitrous oxides
What normally happens with the suns radiation?
It passes through the atmosphere, absorbed by the earths surface and re-radiated as heat
How does the greenhouse effect affect earth?
The gasses prevent the thermal energy radiating out of the earths atmosphere, causing it to heat up
How is the greenhouse effect affecting us? (6 factors)
- polar ice sheets melting- causing sea levels to rise
- some areas having less water - causing droughts, food shortages and desertification
- longer growing seasons- faster crop growth due to Co2 levels rising
- severe weather events
- tropical diseases
- agricultural pests - thriving In the warmer environment
What is the carbon cycle?
How carbon moves between stores through various processes
Name 5 processes In the carbon cycle
- respiration
- photosynthesis
- combustion
- feeding
- decomposition
What are carbon sinks?
Where carbon can be stored
(e.g ocean,plant matter,soil etc.)
Name 5 natural recourses
- biological resources (plants and animals)
- land
- fossil fuels
- metal ores and other minerals
- water
Define renewable resources
Resources that are naturally replenished within a human lifetime
Define non renewable resources
Resources that will run out or will not be naturally replenished during a human lifetime
What is the reactivity series used for?
The reactivity of a metal determines the method of extraction
In order, name the metals in the reactivity series (remember the pneumonic )
Potassium
Sodium
Calcium
Magnesium
Aluminium
Carbon
Zinc
Lead
Copper
Silver
Gold
If a metal is above carbon on the reactivity series, how will it be extracted?
By electrolysis
If a metal is below carbon ( not including gold or silver ) how will it be extracted?
By reduction using carbon (e.g)
What two metals do not need to be extracted and why?
Silver and Gold because they occur native
How does electrolysis work?
The ore is melted and electricity passed through it - this separates it into the metal and oxygen
How does reduction work
Heating the ore with carbon will cause the carbon to react with the oxygen and leave the metal behind
What is reduction also called?
Carbon displacement
Other than gold and silver what other metal is found natively?
Platinum
Name 4 pros of recycling metals
- relatively easy
- saves valuable raw materials- reserves of metal ores will last longer
- less energy is needed to produce a metal
- less damage to the environment- fewer quarries and mines,less noise and less heavy traffic
Name one way of recycling plastics that can be heated and remoulded into a new shape
Thermosoftning ( e.g acrylic )
How can plastics that cannot be easily remoulded be recycled
Thermosetting ( e.g. PET )
What is sustainability?
The ability for the natural world and human civilisation to coexist indefinitely
How can sustainability be reached?
The resources we use are replenished/recycled and have little impact on the environment
Is it more energy efficient to extract or recycle materials?
Some products use nearly ,as much energy as is needed to extract, collecting and processing the material, however generally it is more efficient to recycle
What is an example of a material where it is more expensive to recycle?
Glass - recycling glass saves 30% of the energy needed to make new glass but the cost of setting up and running a glass recycling centre means it is more expensive
What is an example of a material that recycling it is profitable and saves a lot of energy?
Aluminium - recycling aluminium saves 95% of energy and is highly profitable
What is down cycling?
When the material is recycled and a new product is made that itself cannot be recycled
