Earth's Crust and Plate Tectonics

The four layers that make-up the earth’s composition are

• Crust, Lithosphere, Mesosphere and Core
• Lithosphere, Asthenosphere, Mantle and Core
• Crust, Mantle, Outer Core and Inner Core
• Mantle, Outer Core, Lithosphere and Crust

Large pieces of lithosphere that move around on the asthenosphere are called

• Crust plates
• Tectonic plates
• Mantle pieces
• Core plates

The hypothesis that land masses spread apart from each other and have done so in the past is known as

• Divergent Plate Boundary 
• Tension
• Uplift
• Continental drift

Where does sea-floor spreading take place?

• Convergent Boundaries
• Transform Boundaries
• Land Boundaries
• Mid-Oceanic Ridges

The core is made-up of what two elements?

• iron and nickel
• iron and oxygen
• nickel and silicon
• oxygen and silicon

What is the thinnest layer of the earth’s composition?

• mantle
• inner core
• crust
• outer core

The thickest layer of the earth is the 

• crust
• mantle
• inner core
• outer core

When the crust sinks down into the mantle, what happens to it?

• It becomes a tectonic plate.
• It slowly floats up.
• It sinks to the inner core.
• It melts.

The order of the earth’s compositional layers from most dense to least dense are:

• Inner Core, Crust, Mantle and Outer Core
• Crust, Mantle, Outer Core and Inner Core
• Inner Core, Outer Core, Mantle and Crust
• Crust, Outer Core, Inner Core and Mantle.

What type of boundary occurs when two tectonic plates slide past each other horizontally?

• divergent
• convergent
• transform
• uplift