Topic 8: Earth Science

Question 1

What were the gases in the early atmosphere?

Answer 1

Mostly carbon dioxide water vapour some nitrogen little or no oxygen

Question 2

How was the early atmosphere formed?

Answer 2

Intense volcanic activity released gases

Question 3

How did oceans form?

Answer 3

Water vapour condensed as Earth cooled

Question 4

How was carbon dioxide removed from the atmosphere?

Answer 4

Dissolved in oceans formed carbonates used by marine organisms

Question 5

What happened to carbonates in oceans?

Answer 5

They precipitated formed sediments or became shells skeletons

Question 6

What effect did photosynthesis have on the atmosphere?

Answer 6

Removed carbon dioxide and increased oxygen

Question 7

When did algae first evolve?

Answer 7

2 point 7 billion years ago

Question 8

Why did oxygen levels rise?

Answer 8

Algae and plants photosynthesised over time

Question 9

How did life become more complex?

Answer 9

Oxygen enabled complex organisms to evolve

Question 10

What is the test for oxygen?

Answer 10

Insert glowing splint into gas

Question 11

What is a positive test for oxygen?

Answer 11

Glowing splint relights

Question 12

What is the word equation for photosynthesis?

Answer 12

Carbon dioxide plus water produces glucose and oxygen

Question 13

What is the symbol equation for photosynthesis?

Answer 13

6CO2 plus 6H2O produces C6H12O6 plus 6O2

Question 14

What is the greenhouse effect?

Answer 14

Warming of Earth due to gases trapping infrared radiation

Question 15

Describe how the greenhouse effect works step by step

Answer 15

Sun emits EM radiation Earth absorbs some and re-emits infrared some escapes some is absorbed and re-emitted by greenhouse gases

Question 16

Why is the greenhouse effect important?

Answer 16

Keeps Earth warm enough for life around 14 degrees

Question 17

What is the enhanced greenhouse effect?

Answer 17

Additional warming caused by increased greenhouse gases from human activity

Question 18

How does human activity increase carbon dioxide?

Answer 18

Burning fossil fuels deforestation combustion

Question 19

How does human activity increase methane?

Answer 19

Landfill digestive processes in animals rice farming

Question 20

What evidence shows that greenhouse gases trap heat?

Answer 20

CO2 absorbs infrared satellites show as CO2 rises outgoing infrared decreases

Question 21

Why is historical climate data less accurate?

Answer 21

Fewer locations less reliable instruments older methods

Question 22

What is the difference between accurate and precise?

Answer 22

Accurate is close to true value precise is consistent or repeatable

Question 23

What are two ways to estimate past climate data?

Answer 23

Gas bubbles in ice cores tree ring growth

Question 24

How do gas bubbles in ice estimate climate?

Answer 24

They trap past air samples showing CO2 and other gas levels

Question 25

How do tree rings estimate past climate?

Answer 25

Wider rings show warmer wetter years narrower rings show cooler drier years

Question 26

What are some effects of climate change?

Answer 26

Rising sea levels melting ice more extreme weather habitat loss drought

Question 27

What is mitigation?

Answer 27

Reducing or preventing climate change by cutting emissions

Question 28

What are examples of mitigation?

Answer 28

Using renewable energy improving energy efficiency protecting forests

Question 29

What is adaptation?

Answer 29

Adjusting to effects of climate change

Question 30

What are examples of adaptation?

Answer 30

Flood barriers new farming techniques drought-resistant crops irrigation

Question 31

What is correlation?

Answer 31

A pattern or link between two variables

Question 32

What is causation?

Answer 32

One variable directly causes a change in another

Question 33

Why do people confuse correlation with causation in climate science?

Answer 33

Because media oversimplifies complex scientific models