C2.4 The Earth Flashcards
What percentage of the Earth’s atmosphere is oxygen?
21%
What percentage of the Earth’s atmosphere is nitrogen?
78%
Which other gases make up the other 1% of the atmosphere?
Water vapour, carbon dioxide, methane
Name the three types of rock
Sedimentary, metamorphic, igneous
What are the properties of sedimentary rocks?
They are soft and porous
How does freeze thaw occur?
Water gets into the rocks and expands breaking the rock
How does chemical weathering occur?
Acid rain reacts with the rocks
How does biological weathering occur?
Plant roots grow into the rocks breaking them
What is erosion?
Where rocks are broken down into sediment
What is transport?
Where water moves sediment to rivers and seas
What is deposition?
Where sediment falls to the bottom of sea or river beds
What is compaction?
When layers of sediment build up they press down on each other pushing out water
How are sedimentary rocks formed?
Rocks are eroded and the sediment is transported to rivers and seas. The sediment is deposited and over many years it is compacted to form sedimentary rocks
What are the properties of igneous rocks?
Hard, not porous, made of crystals
How are igneous rocks formed?
By cooling lava or magma
What are the properties of metamorphic rocks?
Hard, not porous and made of crystals
How are metamorphic rocks formed?
By heat and pressure
Name 4 ways carbon dioxide is taken out of the atmosphere
- Photosynthesis
- Dissolving in oceans
- Locked up in sedimentary rocks
- Locked up in fossil fuels
Name 2 ways carbon dioxide is released into the atmosphere
- Respiration
- Burning fossil fuels
How is oxygen put back into the atmosphere?
Photosynthesis
Name the three greenhouse gases
Carbon dioxide, methane, water vapour
What is global warming?
An increase in the Earth’s average temperature
What is climate change?
A long term change in weather
