Structure of the Earth

What is the primary composition of the Earth's inner core?

• Iron and nickel

• Silicon and oxygen

• Carbon and hydrogen

• Magnesium and aluminum

Why is the Earth's outer core in a liquid state?

• It is closer to the sun

• It is composed of water

• It is made of lighter elements

• It is under less pressure than the inner core

What is the term for molten rock found in the Earth's mantle?

• Magma

• Sediment

• Basalt

• Lava

How thick is the Earth's crust on average?

• 300 to 500 kilometers

• 100 to 200 kilometers

• 5 to 70 kilometers

• 700 to 1000 kilometers

What are the large sections of the Earth's crust called?

• Islands

• Ridges

• Plates

• Continents