Atmosphere

Question 1

Nitrogen

Answer 1

78%

Question 2

Oxygen

Answer 2

21%

Question 3

How did the atmosphere form

Answer 3

• intense volcanic activity released gases that form atmosphere
• water vapour was one that condensed to make oceans
• volcanoes also release lots of co2 and little oxygen

Question 4

How did co2 drop

Answer 4

• co2 dissolved in ocean
• weak acid which reacted with minerals
• precipitates which over time formed sediments of carbonate rock
• some co2 used to form corals and shells
  = when they die it formed sedimentary rock limestone
  = removed co2

Question 5

How did o2 increase

Answer 5

• photosynthetic algae first evolved in oceans
  = plants evolved
  = worked through respiration
  = increases o2
  = allows animals to evolved
  = after a while decrease co2 levels

Question 6

Describe a fuel

Answer 6

Releases energy when they’re combusted
Eg coal and hydrocarbons

Question 7

What happens when we burn fuels with carbon and hydrogen

Answer 7

Carbon and hydrogen atoms react with o2 in the air
= elements oxidised

Question 8

Product of complete combustion

Answer 8

Co2

Question 9

Products of incomplete combustion

Answer 9

Co2 and toxic gas
= both form water vapour

Question 10

Describe oxides of nitrogen

Answer 10

Oxides of nitrogen produced in engines eg cars
= high temps cause nitrogen and oxygen to react
= produces range of different molecules
= called oxides of nitrogen

Question 11

Effects of sulphur dioxide and oxides of nitrogen

Answer 11

Cause breathing problems
= also dissolve in rain water to form acid rain
= damages trees and corrodes buildings made from limestone

Question 12

Effects of combustion of deisel

Answer 12

Carbon particulates
= lung and heart disease
Reduces amount of energy from the sun that reaches earths surface
= global dimming
= affect rainfall patterns

Question 13

How acid rain forms

Answer 13

Sulphur reacts with oxygen to form sulphur dioxide
= dissolves in rainwater
= forms acid rain
= erodes limestone