The Earth’s Atmosphere

Question 1

What was the atmosphere like billions of years ago?

Answer 1

Mainly carbon dioxide, nitrogen, water vapour and hydrogen based compounds

Question 2

What did volcanoes release in the early atmosphere?

Answer 2

Carbon dioxide, water vapour and nitrogen

Question 3

What happened when the Earth cooled?

Answer 3

Water vapour condensed and formed oceabs

Question 4

How else was water brought to Earth?

Answer 4

Comets

Question 5

What appeared 3.4 billion years ago?

Answer 5

Bacteria like organisms that used chemosynthesis to make energy

Question 6

When did bacteria like organisms evolve into photosynthesising bacteria and algae?

Answer 6

2.7 billion years ago

Question 7

How did photosynthesising organisms change the atmosphere?

Answer 7

By adding oxygen

Question 8

What happened when plants and animals began to evolve?

Answer 8

Oxygen levels increases and carbon dioxide levels decreased

Question 9

How much nitrogen is in the atmosphere today?

Answer 9

78%

Question 10

How much oxygen is in the atmosphere today?

Answer 10

21%

Question 11

How much carbon dioxide is in the atmosphere today?

Answer 11

0.04%

Question 12

How much argon is in the atmosphere today?

Answer 12

0.9%

Question 13

How much of other gases is in the atmosphere today?

Answer 13

0.06%

Question 14

Why did nitrogen levels build up?

Answer 14

Nitrogen is very unreactive

Question 15

What is the equation for methane reacting with oxygen in the early atmosphere?

Answer 15

Methane + Oxygen —> Carbon Dioxide + Water

CH4 + 2O2 —> CO2 + 2H2O

Question 16

What is the equation for ammonia reacting with oxygen in the early atmosphere?

Answer 16

4NH3 + 3O2 —> 2N2 + 6H2O

Question 17

Why did carbon dioxide levels decrease?

Answer 17

It got trapped in organisms, fossils, crude oils, etc

Question 18

What are the main greenhouse gases?

Answer 18

Carbon Dioxide, Methane and Water Vapour

Question 19

What are the fossil fuels?

Answer 19

Coal, oil and gas

Question 20

What is the equation for burning fossil fuels?

Answer 20

Fossil fuels + oxygen —> carbon dioxide + water

Question 21

What increases carbon dioxide in the atmosphere?

Answer 21

Burning wood, cattle farming, burning fossil fuels, deforestation

Question 22

What is air pollution?

Answer 22

The presence of harmful substances in the environment

Question 23

How does carbon dioxide affect the environment?

Answer 23

Climate change, raises earth’s temperature by trapping infrared radiation

Question 24

How does carbon monoxide affect the environment?

Answer 24

Decreases the ability of the blood to carry oxygen leading to death

Question 25

Where does carbon monoxide come from?

Answer 25

Incomplete combustion of fossil fuels

Question 26

Where does sulphur dioxide come from?

Answer 26

Burning fossil fuels containing sulphur

Question 27

How does sulphur dioxide affect the environment?

Answer 27

Combines with water vapour in the air to cause acid rain

Question 28

How do nitric oxides affect the environment?

Answer 28

Combine with water vapour to form acid rain

Question 29

Where do nitric oxides come from?

Answer 29

Lightning, road traffic, power plants

Question 30

Where do particulates come from?

Answer 30

Burning fossil fuels and wood

Question 31

How does particulates affect the environment?

Answer 31

Cause breathing difficulties, global dimming, dirty looking environment