Q.1
Why is nitrogen used in food packaging?
  • It makes the food lighter and easier to transport
  • It is cheaper than using all of the air
  • It makes food taste a lot better
  • It is unreactive and helps to keep the food fresher
Q.2
One theory is that life on Earth started from chemicals in the early atmosphere. According to that theory, which chemicals are thought to have been involved?
  • Methane and carbon dioxide
  • Ammonia and oxygen
  • Ammonia and hydrocarbons
  • Hydrocarbons and oxygen
Q.3
Argon is a noble gas and is inert (does not react with other substances). For that reason it is used in light bulbs but how is it obtained from the air?
  • The air is solidified and argon is collected as the solid air sublimes
  • The air is liquified and argon can be collected by fractional distillation
  • It can be filtered out from the air by using a special filter
  • It is made from other chemicals
Q.4
About how much oxygen is there in the atmosphere?
  • 78%
  • 62%
  • 43%
  • 21%
Q.5
What may have happened to the rest of the carbon dioxide from the early atmosphere?
  • It has been lost into space
  • It has been changed into other gases by radiation from the Sun
  • It was absorbed by the oceans and then has been locked into rocks like limestone
  • It has been absorbed by lava from volcanoes
Q.6
What natural process is thought to have created the early atmosphere and which was the main gas?
  • Volcanic action created the early atmosphere and carbon dioxide was the main gas
  • Photosynthesis created the early atmosphere and oxygen was the main gas
  • Cosmic rays created the early atmosphere and nitrogen was the main gas
  • Global warming created the early atmosphere and carbon dioxide was the main gas
Q.7
The first green algae-like plants evolved about 2,000 million years ago. How would this have affected the early atmosphere?
  • It reduced the carbon dioxide levels and increased the amount of oxygen
  • It started to fix nitrogen into the soil
  • It converted methane into ammonia which was then converted to oxygen by animals
  • It would not have caused any changes to the early atmosphere
Q.8
About how much of the atmosphere is nitrogen?
  • 78%
  • 62%
  • 43%
  • 21%
Q.9
As well as the main gases, which of the following are found in the atmosphere in small proportions?
  • Argon
  • Carbon dioxide
  • Water vapour
  • All of the above
Q.10
The level of carbon dioxide in the atmosphere has remained almost the same for 200 million years. Since the start of the twentieth century it has increased dramatically. What is thought to have caused this?
  • The increase in population
  • The development of the motor car
  • Nuclear power stations
  • The steel making industry
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