Earth and atmospheric science

Question 1

What was earth’s early atmosphere said to have

Answer 1

• little to no oxygen
• large amounts CO2
• water vapour
• small amounts of other gases

Question 2

How were gases that form earth’s early atmosphere made

Answer 2

volcanic activity

Question 3

What is evidence for little to no oxygen in earth’s early atmosphere

Answer 3

• Pyrite - found in ancient rocks - is broken down by oxygen and therefore only forms if none is present
• Volcanoes don’t produce oxygen
• Rock contained no iron oxide which later was then found proving that at first there was no oxygen to bid with iron in rocks

Question 4

What is evidence for large amounts of carbon dioxide in earth’s early atmosphere

Answer 4

Atmospheres of Mars and Venus are mainly carbon dioxide thought to be released by volcanoes - supports idea that Earth’s early atmosphere also contained lots of carbon dioxide due to high volcanic activity

Question 5

What is evidence for water vapour in earth’s early atmosphere

Answer 5

About 4 billion years ago, the Earth cooled down. This caused water vapour to condense to liquid water which formed oceans.

Question 6

What is evidence for small amounts of other gases in earth’s early atmosphere

Answer 6

Mixture of gases released by volcanoes

Question 7

How did oceans form

Answer 7

Condensation of water vapour which formed liquid water and fell as rain

Question 8

Explain how the amount of carbon dioxide in the atmosphere was decreased

Answer 8

• CO2 dissolved in the water
• Sea creatures used the carbon dioxide to form shells made from calcium carbonate

Question 9

Explain how the growth of primitive plants increased oxygen in the atmosphere

Answer 9

Algae & plants photosynthesised absorbing carbon dioxide and releasing oxygen

Question 10

What is the test for O2

Answer 10

Glowing splint relights in the presence of oxygen

Question 11

Describe the greenhouse effect

Answer 11

1. EM radiation from the sun passes through the earth’s atmosphere
2. Earth absorbs some radiation some is is refracted as Infrared
3. IR is absorbed by greenhouse gases warming up the atmosphere

Question 12

What evidence is there for human activity causing climate change

Answer 12

• change in atmospheric CO2 conc
• fossil fuel emission
• temperature increase

Question 13

What day to day activities increase levels of CO2

Answer 13

• Driving
• Consuming electricity

Question 14

What day to day activities increase levels of CH4

Answer 14

• Raising livestock cows
• Decay of organic waste

Question 14

What implications does human activities have on the earth

Answer 14

increase of earth temperature (global warming) inevitably leading to climate change