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C9: Quiz 1 – Answers
C9: Quiz 1 – Answers
1)
a) For the last 200 million years
b) Nitrogen is 78-80% and oxygen is 20-21%
c) Any 2 from carbon dioxide, water vapour and any of the noble gases (helium, neon, argon etc)
2) The atmosphere has evolved over billions of years, which makes it hard to find evidence from that long ago
3) Volcanic activity releases nitrogen into the atmosphere. Nitrogen is very unreactive, so the level of nitrogen in the atmosphere has increased over time
4)
a) Photosynthesis (by plants and algae)
b) carbon dioxide + water –> glucose + oxygen
5)
a) Carbon dioxide was the most common gas. It was produced by volcanic activities
b) The water vapour in the atmosphere condensed creating the oceans
6) Any three from
7)
a) Dead plankton sinks to the bottom of the sea or lakes. The dead plankton then gets buried in layers of mud and sediment, which prevents oxidisation as there is little or no oxygen under the mud/ sediment. Over millions of years at a high temperature and pressure, the dead plankton becomes crude oil
b) Coal is a fossil fuel which is formed from dead trees. The dead trees are buried by flooding, which prevented oxidation of the wood taking place due to a lack of oxygen. Over millions of years of compression and heat, the dead trees turned into coal
c) Limestone is made from shells and skeletons of marine organisms
a) For the last 200 million years
b) Nitrogen is 78-80% and oxygen is 20-21%
c) Any 2 from carbon dioxide, water vapour and any of the noble gases (helium, neon, argon etc)
2) The atmosphere has evolved over billions of years, which makes it hard to find evidence from that long ago
3) Volcanic activity releases nitrogen into the atmosphere. Nitrogen is very unreactive, so the level of nitrogen in the atmosphere has increased over time
4)
a) Photosynthesis (by plants and algae)
b) carbon dioxide + water –> glucose + oxygen
5)
a) Carbon dioxide was the most common gas. It was produced by volcanic activities
b) The water vapour in the atmosphere condensed creating the oceans
6) Any three from
- dissolved into the oceans
- photosynthesis from algae and plants
- becoming carbon compounds in organisms (shells & skeletons)
- becoming locked up in sedimentary rocks/ fossil fuels
7)
a) Dead plankton sinks to the bottom of the sea or lakes. The dead plankton then gets buried in layers of mud and sediment, which prevents oxidisation as there is little or no oxygen under the mud/ sediment. Over millions of years at a high temperature and pressure, the dead plankton becomes crude oil
b) Coal is a fossil fuel which is formed from dead trees. The dead trees are buried by flooding, which prevented oxidation of the wood taking place due to a lack of oxygen. Over millions of years of compression and heat, the dead trees turned into coal
c) Limestone is made from shells and skeletons of marine organisms
Questions
1)
a) For how many years has the earth’s atmosphere been like it is today?
b) Roughly, what percentage of the earth’s atmosphere is nitrogen and what percentage is oxygen?
c) Name 2 other gases in the earth’s atmosphere.
2) Why is it hard for scientists to say for certain how the atmosphere on earth has evolved?
3) The level of nitrogen in the atmosphere has increased over time. Which activity produces nitrogen and why has the levels of nitrogen increased over time?
4)
a) Which process has caused the level of oxygen in the atmosphere to increase?
b) Write the chemical word equation for this process.
5)
a) In the early atmosphere, which gas was the most common and what process produced this gas?
b) As the earth cooled, what happened to the water vapour in the atmosphere?
6) The concentration of carbon dioxide in the atmosphere has decreased over time. Give three reasons why the concentration of carbon dioxide has decreased over time.
7)
a) How is crude oil created?
b) How is coal created?
c) What is limestone made from?
1)
a) For how many years has the earth’s atmosphere been like it is today?
b) Roughly, what percentage of the earth’s atmosphere is nitrogen and what percentage is oxygen?
c) Name 2 other gases in the earth’s atmosphere.
2) Why is it hard for scientists to say for certain how the atmosphere on earth has evolved?
3) The level of nitrogen in the atmosphere has increased over time. Which activity produces nitrogen and why has the levels of nitrogen increased over time?
4)
a) Which process has caused the level of oxygen in the atmosphere to increase?
b) Write the chemical word equation for this process.
5)
a) In the early atmosphere, which gas was the most common and what process produced this gas?
b) As the earth cooled, what happened to the water vapour in the atmosphere?
6) The concentration of carbon dioxide in the atmosphere has decreased over time. Give three reasons why the concentration of carbon dioxide has decreased over time.
7)
a) How is crude oil created?
b) How is coal created?
c) What is limestone made from?