Changing Earth Quiz

Approximately how long ago did the Earth form?

• 3 million years ago

• 4.54 billion years ago

• 20 million years ago

• 100 million years ago

What is the outermost layer of the Earth called?

• The mantle

• The inner core

• The crust

• The outer core

What causes the tectonic plates of the Earth's crust to move?

• They float on the semi-solid mantle beneath them

• They are pushed by the Earth's rotation

• They are pulled by the moon's gravity

• They move due to the Earth's magnetic field

Which layer of the Earth is the thickest?

• The crust

• The mantle

• The inner core

• The outer core

What is the state of the Earth's inner core?

• Liquid

• Semi-solid

• Molten

• Solid

Which two metals are primarily found in the Earth's core?

• Iron and nickel

• Copper and zinc

• Aluminum and silver

• Gold and platinum

Approximately how long will Earth remain habitable for most organisms before the sun's natural evolution makes it unlivable?

• About 1.3 million years

• About 4.5 billion years

• About 1.3 billion years

• About 4.5 million years

What is the most abundant gas in the Earth's atmosphere?

• Oxygen

• Argon

• Nitrogen

• Carbon dioxide

What percentage of the Earth's atmosphere is composed of oxygen?

• 78%

• 1%

• 21%

• 0.04%

Why have the levels of carbon dioxide in the atmosphere increased over time?

• Due to a decrease in human population

• Because of more forests being planted

• Due to an increase in human population and activities like burning fossil fuels

• Because of increased photosynthesis in forests