C1.7 Our Changing Planet

Question 1

What are the layers of earth?

Answer 1

Inner core
Outer core
Mantle
Crust

Question 2

How thick is the crust?

Answer 2

6-35 km

Question 3

How thick is the mantle?

Answer 3

3000km

Question 4

How thick is the core?

Answer 4

3500km

Question 5

What’s the crust?

Answer 5

Rocky outer layer beneath your feet. It’s where we get our minerals.

Question 6

What’s the mantle?

Answer 6

Semi-liquid, very high temperatures
The cooler section near the crust is less mobile than the hotter section next to the core. It has properties of a solid but can flow very slowly.

Question 7

What’s the core?

Answer 7

The layer at the centre of the earth. This layer is divided into two sections: the liquid outer core and the solid inner core. It’s a mixture of magnetic metals: nickel and iron.

Question 8

What are Seismic waves?

Answer 8

S waves which only travel through solids and P waves travel through the earth and are refracted when they pass through a medium.
These are how they know what’s in the earth and the layers.
S-waves are transverse and P-waves are longitudinal
Both waves can be detected in an earthquake

Question 9

How much do continents move per year?

Answer 9

A couple of centimetres

Question 10

Who’s Alfred Wegener?

Answer 10

Discovered the theory of plate tectonics, continental drift in 1911. It took over 20 years to be accepted.

Question 11

How is convection formed in earth?

Answer 11

The earths radioactive core releases large amounts of heat energy, which heats the rock in the lower mantle. It becomes less dense and rises.
The warmer rock in the lower mantle begins to rise, while the cooler rock in the upper mantle sinks. This movement of rock means that circulating convection currents are formed within the mantle.
As the mantle heats up, energy transfer from the convection currents causes the earths crust to heat up. This heating drives the movement of the tectonic plates and causes the continents to move a few centimetres each year.

Question 12

How are earthquakes formed?

Answer 12

When the boundaries meet, huge stresses build up.
These forces make the plates buckle and deform which can create mountains.
If the plates suddenly slip past each other, earthquakes may form.

Question 13

Why don’t scientists know when earthquakes will occur?

Answer 13

They don’t know what happens under the crust
Don’t know where forces and pressures build up
Don’t know the sizes of the forces
Don’t know when the sizes reach their limit

Question 14

What are the gases in our atmosphere and the percentages of them?

Answer 14

Oxygen - 21%
Carbon dioxide - 0.04%
Nitrogen - 78%
Argon - 0.9%

Question 15

When did the earth form?

Answer 15

4.5 billion years ago

Question 16

What happened 4 billion years ago?

Answer 16

There was a lot of volcanic activity and release nitrogen, CO2 and water which make a dangerous atmosphere

Question 17

What happened 3.4 billion years ago?

Answer 17

Tiny photosynthesis bacteria are everywhere. They give out oxygen and waste gas. The concentration of oxygen was 0.001%

Question 18

What happened 600 million years ago?

Answer 18

0.21% of oxygen and bacteria was thriving more.

Question 19

What happened 400million years ago?

Answer 19

Land plants start to appear and produce more oxygen - 2.1%

Question 20

How long has the oxygen level stayed the same?

Answer 20

200 million years

Question 21

What are amino acids?

Answer 21

Any of a large number of compounds found in living cells contain carbon, oxygen, hydrogen and nitrogen and come together to form proteins.

Question 22

What’s the primordial soup theory?

Answer 22

It states that billions of years ago the earths atmosphere was rich in nitrogen, hydrogen, ammonia and methane. Lightning struck, causing a chemical reaction between the gases, resulting in the formation of amino acids. The amino acids collected in a ‘primordial soup’ - a body of water out of which life gradually crawled. The amino acids gradually combine and make organic matter.

Question 23

What and when was the Miller-Urey Experiement?

Answer 23

1953
They combined water, hydrogen, methane and ammonia. They sparked them (like lightening). This formed amino acids which is the block of living things. They found out how life on Earth supposedly started. They found 11 amino acids and in 2008 scientists analysed it again and found 22 amino acids.

Question 24

Why don’t some people agree with the Miller Urey experiment?

Answer 24

People believe oxygen was present before the time and Miller and Urey didn’t use oxygen.
No one knows exactly what the atmosphere was like.
There might not have been continuous lightening.

Question 25

What’s the Murchison Theory?

Answer 25

In 1969 a meteorite fell from the sky above Australia. It weighed over 100kg
We have identified over 70 amino acids on the fragments
Therefore the acids could have come from space, extraterrestrial seeding.

Question 26

What are volcanic vents?

Answer 26

From volcanoes there was the correct environment for amino acids to form.

Question 27

Where has carbon dioxide gone?

Answer 27

Locked up in sedimentary rock, such as limestone and fossil fuels.
Absorbed by plants for photosynthesis.
Dissolved in the oceans.

Question 28

What happened to methane and ammonia?

Answer 28

They reacted with oxygen.

Methane+oxygen->carbon dioxide+water

Ammonia+oxygen->nitrogen+water

Question 29

What do we use nitrogen for?

Answer 29

Make ammonia
Inert(Unreactive)- used in food
Packaging
Used to cool things

Question 30

What do we use argon for?

Answer 30

Very inert (Unreactive)
Light bulbs

Question 31

What do we use oxygen for?

Answer 31

Hospital - breathing

Welding - binding metals

Question 32

What do we use co2 for?

Answer 32

Stage shows- dry ice

Cools things

Question 33

Draw the carbon cycle.

Answer 33

Look it up :)

Animals in the middle
Fossil fuels to the right
Carbon dioxide at the bottom
Plants to the left
Dead organisms at the top

Question 34

What’s carbon capture?

Answer 34

Instead of being released into the atmosphere, carbon dioxide is capture at power stations and compressed. The CO2 is pumped through a network of pipelines. It’s then pumped down through the well into porous rock which previously held gas deep beneath the sea bed. The CO2 filters into the porous sandstone reservoir, filling the ring spaces which once held natural gas. It is trapped from escaping by the layers of solid rock above.

Question 35

What’s a tectonic plate?

Answer 35

The sections of the earths crust