Clean Air

Question 1

What makes up Earth’s atmosphere today

Answer 1

Clean air:

78% nitrogen
21% oxygen
1% other gases
With water vapour and some polluting gases

Question 2

Describe earths changing atmosphere

Answer 2

Earliest atmosphere contained ammonia and carbon dioxide found inside earth, often released from volcanoes
4bl years ago-temperature of planet dropped, water vapour condensed to form seas and oceans
2bl years ago- evolution of plants meant photosynthesis reduced carbon dioxide and increased oxygen in atmosphere

Question 3

What do cars emit that is pollutive

Answer 3

Carbon monoxide when fuel is not burnt properly (poisonous)
Oxides of nitrogen formed in the internal combustion engine (acid rain
Unburned hydrocarbons (creates smog)

Question 4

Pollutant gases are formed from

Answer 4

Incomplete combustion in a car engine

Burning of fossil fuels

Question 5

What do catalytic converters do in cars

Answer 5

Converts carbon monoxide into carbon dioxide

Question 6

How is acid rain formed

Answer 6

When coal and oil burns, sulphur impurities produce sulphur dioxide and nitrogen dioxide.

They dissolve in water

Question 7

What do fossil fuels burnt increase in the atmosphere

Answer 7

Carbon dioxide

Question 8

Why is there more carbon dioxide in the atmosphere

Answer 8

Excessive burning of fossil fuels with deforestation so less photosynthesis to convert the carbon dioxide

Increasing population makes these factors worse

Question 8

Unburnt hydrocarbons can cause

Answer 8

Smog in the atmosphere

Question 9

How do living things reduce oxygen levels and increase carbon dioxide levels in the atmosphere

Answer 9

By respiring

Question 10

Why do the carbon dioxide and oxygen levels remain constant

Answer 10

Plants and animals always respire but in the day plants photosynthesise too

Question 11

How can we remove carbon monoxide from car exhaust

Answer 11

Fit catalytic converter to react carbon monoxide to produce carbon dioxide instead.

Carbon dioxide can be used for photosynthesis

Question 12

What gas to aerosols produce

Answer 12

CFCs which damage ozone

Question 13

What does acid rain do

Answer 13

Erode stonework and corrode metals

Make rivers and lakes acidic and kill aquatic life and plants

Question 14

What is the equation for a catalytic converter

Answer 14

Carbon monoxide+ nitrogen oxide > nitrogen + carbon dioxide

2CO + 2NO > N2 + 2CO2