Inside The Earth 📖

Question 1

Lithosphere

Answer 1

The uppermost layer of the earth, it includes the top of the mantle and the crust. It is cool and brittle.

Question 2

Tectonic plates

Answer 2

The earths surface broken into large pieces.

Question 3

Mantle

Answer 3

The middle layer of the earth, between the crust and the core and it’s 2900m thick.

Question 4

Asthenosphere

Answer 4

Part of the earths mantle. It is hot, semi-molten layer that lies beneath the tectonic plates.

Question 5

Core

Answer 5

Part of the earths. The solid centre of the earth. However, the outer core may be liquid not solid.

Question 6

Continental Crust

Answer 6

• Made of thick granite (10-50miles).
• Granite, has a low density.
• Forms the land.

Question 7

Oceanic Crust

Answer 7

• Very thin (1-3miles). High density
• Made of basalt rock.
• Same rock found in the mantle.
• Under the oceans.

Question 8

How old is the earth ?

Answer 8

4.6 billion years old

Question 9

What is the crust made up of ?

Answer 9

Tectonic plates

Question 10

How thick is the mantle ?

Answer 10

2900km thick

Question 11

How many layers are in the mantle ?

Answer 11

• Two upper and lower (two parts to upper mantle).

Question 12

State two properties about the outer core ?

Answer 12

• 2266km

- 4000°c - 5700°c

Question 13

Two properties about the inner core

Answer 13

Mostly solid, 1200km radius, iron and nickel.

Question 14

The earths heat engine

Answer 14

• We know the inside of the earth is hot because only very high temperatures can create those rocks.
• It’s over 5000°c because the rocks have to get used to high temperatures so they don’t melt.

Question 15

Radioactive Decay

Answer 15

50% of the earths heat, some elements unstable e.g. uranium, atoms of these elements release particles from the nuclei to give off heat, this is called radioactive decay.