Earth's Layers and Composition

What was a common early idea about what the Earth was made of inside?

• A giant ball of water

• Uniform rock throughout

• A hollow sphere

• Mostly gas

What did Sir Isaac Newton suggest about the material inside Earth compared to the surface rock?

• It is much lighter

• It is exactly the same

• It is much denser

• It is mostly air

How did scientists in the early 1900s get clues about what is deep inside the Earth?

• By digging very deep holes

• By studying rocks from space

• By analyzing waves from earthquakes

• By observing volcanoes

When different materials settle, like in the jar experiment, where do the most dense materials go?

• They float to the top

• They stay mixed evenly

• They sink to the bottom

• They evaporate

Which layer of Earth is the outermost, solid, and thinnest, like the shell of an egg?

• The mantle

• The outer core

• The inner core

• The crust

Which part of Earth's crust is usually thicker?

• Oceanic crust

• Continental crust

• Both are the same thickness

• The mantle

What is the largest layer of the Earth by volume?

• The crust

• The mantle

• The core

• The ocean

What two main metals make up the Earth's core?

• Oxygen and Silicon

• Aluminum and Magnesium

• Iron and Nickel

• Calcium and Sodium

What two parts of the Earth combine to form the lithosphere?

• The mantle and the core

• The crust and the outer core

• The crust and the upper part of the mantle

• The inner core and the outer core

What is the state of matter of the Earth's outer core?

• Solid

• Gas

• Plasma

• Liquid