Layers of Earth Pre Assessment

Which of the following lists Earth's layers in order from outermost to innermost?

• inner core, outer core, mantle, crust

• mantle, outer core, inner core, crust

• crust, mantle, outer core, inner core

Answer explanation

Which best describes the mantle?

• molten (melted) metal

• hot, slow flowing rock

• dry land and ocean floor

Answer explanation

The mantle is made of a very viscous rock made of iron, nickel, silicon, aluminum, and magnesium.

What do geologists call the crust and uppermost mantle?

• lithosphere

• mesosphere

• asthenosphere

Answer explanation

The lithosphere is the uppermost mantle and all of the crust.

Which layer is responsible for Earth’s magnetic field?

• inner core

• outer core

• mantle

Answer explanation

The liquid metal that makes up the outer core passes through a magnetic field, which causes an electric current to flow within the liquid metal...in turn, it creates its own magnetic field.

Which of Earth’s layers is the thickest?

• core

• crust

• mantle

Answer explanation

At 1,800 miles thick, the mantle makes up more

than 84% of Earth’s total volume.

Which of Earth’s layers is the coldest?

• crust

• mantle

• core

Answer explanation

In which layer is the asthenosphere located?

• mantle

• core

• crust

Answer explanation

The asthenosphere is the highly viscous, soft and flowing region of the upper mantle of the Earth.

As you go deeper down inside Earth, what happens to the density?

• it increases

• it decreases

• it stays the same

Answer explanation

In which layer do convection currents take place?

• core

• mantle

• crust

Answer explanation

Which layer is the least dense?

• mantle

• crust

• core

Answer explanation