C1: Clean air

Question 1

What is air composed of?

Answer 1

78% nitrogen, 21% oxygen and of the remaining 1% 0.035% is carbon dioxide.

Question 2

Give the 4 main ways carbon dioxide travels around the atmosphere.

Answer 2

Respiration, photosynthesis, combustion, respiration

Question 3

Why do the percentages change very little?

Answer 3

There is a balance between processes that make both carbon dioxide and oxygen.

Question 4

Give two reasons for a rise in CO2 levels.

Answer 4

Deforestation which results in less photosynthesis taking place
An increased population (demand for energy increases).

Question 5

Explain how the early atmosphere came about.

Answer 5

Volcanoes releases gases which were water vapour, carbon dioxide, ammonia and methane.
The water vapour condensed to form the ocean and most of the carbon dioxide dissolved into the sea which help formed the shells and skeletons of marine organisms.
Soon plants formed and photosynthesised which lowered the volume of gas.
Ammonia was broken down by the sun then reacted with oxygen to form nitrogen. Due to nitrogen’s unreactive state we have loads of it.

Question 6

What reaction takes place in a catalyst converter?

Answer 6

2CO + 2NO = N2 + 2CO2