Earth structure

What is the thickness range of the Earth's crust?

• 8 to 65 km

• 100 to 200 km

• 1 to 5 km

• 200 to 300 km

What is the main composition of the Earth's mantle?

• Silicate rocks rich in iron and magnesium

• Pure iron

• Nickel and copper

• Carbon and hydrogen

At what temperature can the bottom of the Earth's crust reach?

• 1200°C

• 5000°C

• 100°C

• 2000°C

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

• Iron with a little nickel

• Silicon and oxygen

• Carbon and nitrogen

• Aluminum and copper

How thick is the oceanic crust?

• 2-10 km

• 10-100 km

• 50-150 km

• 1-5 km

What is the density of the continental crust?

• 2.7 grams per cubic cm

• 3.0 grams per cubic cm

• 1.5 grams per cubic cm

• 4.0 grams per cubic cm

How old is the continental crust?

• As old as 4.3 billion years

• 200 million years

• 1 billion years

• 500 million years

What type of rock is the oceanic crust primarily made of?

• Basalt

• Granite

• Sandstone

• Limestone

What percentage of the Earth's land surface is covered by continental crust?

• 40%

• 60%

• 20%

• 80%

What geological features are found at plate boundaries?

• Earthquakes, volcanoes, and mountain building

• Deserts and plains

• Rivers and lakes

• Forests and jungles