EARTH AND ROCKS - The Earth and its atmosphere

Question 1

What is the nearest part of the atmosphere called?

Answer 1

Troposphere.

Question 2

What is the atmosphere?

Answer 2

A mixture of gases that surrounds the Earth.

Question 3

On average, how high is the troposphere?

Answer 3

10km.

Question 4

What gases is the troposphere mainly made up of?

Answer 4

Nitrogen and Oxygen, and smaller amounts of Argon and Carbon Dioxide.

Question 5

What percentage of the atmosphere is Nitrogen?

Answer 5

78%

Question 6

What percentage of the atmosphere is Oxygen?

Answer 6

21%

Question 7

What percentage of the atmosphere is Argon?

Answer 7

1%

Question 8

What percentage of the atmosphere is Carbon Dioxide?

Answer 8

0.04%

Question 9

Describe phase 1 of how the atmosphere was formed.

Answer 9

1. Earth’s early atmosphere was mostly CO₂ with nearly no oxygen.
2. The Earth’s surface had many volcanoes.
3. Volcanic eruptions released Nitrogen, Water Vapour, Methane and Ammonia.

Question 10

Describe phase 2 of how the atmosphere was formed.

Answer 10

1. Water vapour condensed to form oceans.
2. Lots of CO₂ dissolved in the oceans.
3. Green plants and algae evolved to photosynthesise, taking in CO₂ from the atmosphere.
4. Some CO₂ got locked up in rocks and fossil fuels.

Question 11

Describe phase 3 of how the atmosphere was formed.

Answer 11

1. Photosynthesis released lots of oxygen
2. More oxygen allowed more complex life (like animals) to evolve

Question 12

What is the word equation for photosynthesis?

Answer 12

Carbon dioxide + Water –> Glucose + Oxygen

Question 13

What are the layers of the Earth?

Answer 13

1. Crust
2. Mantle
3. Outer core
4. Inner core

Question 14

Describe the crust.

Answer 14

1. Outer rocky layer
2. 8km - 40km thick

Question 15

Describe the Mantle

Answer 15

1. Beneath the crust
2. Mostly made up of solid rock that can flow
3. Hotter rocks rise and cooler rocks sink (convection currents)

Question 16

What are convection currents?

Answer 16

When hot rocks rise and cool rocks sink in the mantle, causing the tectonic plates to move.

Question 17

Describe the Outer Core.

Answer 17

1. Beneath the mantle
2. Liquid

Question 18

Describe the Inner core.

Answer 18

1. Centre of the Earth
2. Solid

Question 19

How do scientists know the structure of the Earth?

Answer 19

They study:
1. Shock waves from earthquakes.
2. Rocks on the surface and in the oceans.
3. Materials that are brought up by volcanoes.

Question 20

What’s in the crust?

Answer 20

Many elements like (know at least 3):
1. Oxygen
2. Silicon
3. Aluminium
4. Iron
5. Calcium
6. Sodium
7. Magnesium
8. Potassium
9. Titanium
10. Hydrogen