1.7 Changes In The Earth And Atmosphere

Question 1

What is the structure of the earth?

Answer 1

Crust
Mantle
Outer core
Inner core

Question 2

How thick are each parts of the earth?

Answer 2

Crust: 10-200km thick
Mantel: 5800km thick
Outer core: 4200km thick

Question 3

What state is each layer of the earth?

Answer 3

Crust - solid (oceanic or continental)
Mantle - neither solid nor liquid
Outer core - liquid
Inner core - liquid (molten nickel and iron liquid)

Question 4

What is the crust and mantle together?

Answer 4

The lithosphere

Question 5

What is the lithosphere broken into?

Answer 5

Tectonic plates

Question 6

Who came up with a theory about tectonic plates and what was it called?

Answer 6

Alfred Wegner

Continental drift

Question 7

What is continental drift?

Answer 7

The idea that a long time ago all the plates were joined together and had moved apart

Question 8

Why did wegner think the tectonic plates were once together?

Answer 8

He saw the coast lines of south America and and West Africa had similar fossils and rocks

Question 9

Why wasn’t continental drift excepted for so long?

Answer 9

Insufficient evidence

He suggested tidal waves or the earth rotation

Question 10

How did people explain continental drift back then?

Answer 10

A land bridge

Was a reasonable explanation

Question 11

How do tectonic plates actually move?

Answer 11

Convection currents in the mantle

Question 12

How are convection currents caused within the mantle?

Answer 12

Radioactive decay generates heat within the mantle

Question 13

What are the plate boundaries of tectonic plates?

Answer 13

Deconstructive
Constructive
Compressional
Conservative

Question 14

What is a deconstructive plate boundary?

Answer 14

Oceanic and continental plate collide and the oceanic is sub-ducted below the continental

Question 15

What is a constructive plate boundary?

Answer 15

The plates move away from each other

Question 16

What is a compressional plate boundary?

Answer 16

To continental plates collide forcing them upwards creating fold mountains

Question 17

What is a conservative plate boundary?

Answer 17

When two plates slide past each other

Question 18

Why is it difficult for scientists to predict natural disasters?

Answer 18

You can’t see the movement, forces or pressure building up

They don’t know where or when it will be

Question 19

What was the earths conditions like 4 billion years ago?

Answer 19

Intense volcanic activity releasing:
Carbon dioxide
Ammonia
Methane
Water vapour

Question 20

What happened to the water vapour from the early atmosphere?

Answer 20

Condensed into the seas

Question 21

What happened to the carbon dioxide from the early atmosphere?

Answer 21

Carbon dioxide dissolves in the seas
Algae evolved and photosynthesis took in CO2 and produced oxygen
Plants and trees evolved also photosynthesising

Question 22

What happened to the ammonia from the early atmosphere?

Answer 22

In the soil oxygen and bacteria broke down the ammonia giving of Nitrogen

Question 23

How was the ozone layer created?

Answer 23

Oxygen reacted with the lightening

Question 24

What is the ozone layer? What destroys it?

Answer 24

A protective layer in the outermost atmosphere from harmful radiation from the sun

CFC’s not CO2

Question 25

What is stored in sedimentary rocks?

Answer 25

Calcium carbonate

Question 26

What is extracted from sedimentary rocks? What happens when burnt?

Answer 26

Crude oil

When burnt it releases the store of carbon - contributing to global warming

Question 27

What are the percentages of gases in the atmosphere today?

Answer 27

Nitrogen - 78%
Oxygen - 21%
Other gases - 1% (CO2 - 0.03%)

Question 28

What experiment was conducted to recreate early life atmosphere?

Answer 28

Miller-Urey experiment
Or
Primordial soup theory

Question 29

What happened in the Miller-Urey experiment?

Answer 29

The boiled water in a flask
The water vapour was pumped round into a flask with CO2, methane and ammonia were present
They added electrodes (lightening effect)
It went through a condenser allowing amino acids to be collected

Question 30

What did the Miller and Urey conclude from their experiment?

Answer 30

They created amino acids and amino acids are the proteins that lead to life
This is how life began

Question 31

What does the experiment actually conclude?

Answer 31

How amino acids may have been created

Not how life came about

Question 33

What is the air?

Answer 33

A mixture of gases

Question 34

How could you separate the air?

Answer 34

They have different melting and boiling points
So turn them into liquids and use fractional distillation
Then turn them back into gases but now separated

Question 35

Why is fractional distillation of air useful in industry?

Answer 35

Raw materials can be obtained

Question 36

What has to be removed before fractional distillation of air and why?

Answer 36

CO2 and water vapour

They would be solids by -200 which would clog up the pipes

Question 37

What two gases don’t separate completely?

Answer 37

Oxygen and Argon

Question 38

What two gases don’t condense at -200 degrees?

Answer 38

Neon and helium

Their boiling points are -246 and -269

Question 39

Why is the Miller-Urey experiment not 100% accurate?

Answer 39

They can’t know the exact amounts of gas back then and if there was a constant supply of lightening