Earth's Structure

A massive explosion of a star is called . . .

• supernova
• nebula
• pulsar
• black hole

What celestial body eventually evolved into our modern solar system?

• a nebula
• a supernova
• a quasar
• a galaxy

When you spin any mass, what shape will it likely take?

• Sphere
• Disc
• Cylinder
• Cloud

A nebula starts to collapse because of:

• A nearby star shining it's light
• A passing spaceship
• A passing comet
• Gravity

All of the planets started and grew from

• magic
• gas and dust
• large planetesimals
• Small stars

The inner and outer core, mantle, and crust of Earth all have __________.

• been rigid since the formation of Earth
• have the same specific gravity
• different densities
• the same densities

What happened as Earth differentiated during its formative period? 

• Heavier materials sank toward the core, and lighter materials rose.
• Widely separated land areas started looking different from one another.
• The Atlantic and Pacific Oceans developed from the original global ocean.
• Outgassing formed an oxygen atmosphere.

What is Earth's core composed of?

• iron and nickel
• hydrogen and iron
• nickel and silicon
• magnesium and silicon

Why have scientists reasoned that Earth’s outer core is liquid?

• Outer core blocks seismic waves
• Outer core has no effect on seismic waves.
• Outer core diffracts seismic waves
• Outer core amplifies seismic waves.

Which factor accounts for so little iron in the Earth's crust?

• Iron has a high density
• Iron has a low density
• Iron has no density
• Factor other than denisty