Layers of the Earth

How old is planet Earth?

• a) 4.5 thousand years

• b) 4.5 million years

• c) 4.5 billion years

Answer explanation

Earth is approximately 4.5 billion years old.

How many layers are inside the earth?

• 40

• 14

• 4

Answer explanation

Earth has four layers.

The outer layer of the earth is the layer we walk on.

What is this layer made from?

• a) oxygen

• b) rocks

• c) sand

Answer explanation

The outer layer of Earth is made from rocks.

The outer layer of the earth has pieces, much like a jigsaw puzzle.

How many pieces are there?

• 7

• 17

• 27

Answer explanation

The outer layer of Earth has 17 pieces.

The layer beneath the surface of the earth is called the mantle.

What is this layer made from?

• a) silicone rock

• b) liquid metal

• c) water

Answer explanation

The mantle is made from silicone rock.

Beneath the mantle are two layers called the outer core and the inner core.

What are these layers made from?

• a) boiling water

• b) hot gases

• c) iron and nickel

Answer explanation

The outer and inner cores are made from iron and nickel.

How many kilometres is it from the crust of the earth to the inner core?

• a) about 600 kilometres

• b) about 6000 kilometres

• c) about 60 000 kilometres

Answer explanation

It is about 6000 kilometres from the crust to the inner core.

How hot is the inner core of the earth?

• a) about 50 degrees Celsius

• b) about 500 degrees Celsius

• c) about 5000 degrees Celsius

Answer explanation

The inner core of Earth is about 5000 degrees Celsius.