Unit 2A Earth's Layers/Plate Tectonics

1. Which of these statements about Earth's crust is true?

• It is a layer of solid rock that remains the same throughout time.
• It includes the continents, but not the ocean floor.
• It is changing, moving surface with the same thickness everywhere.
• It is a system of large masses called plates that slowly move together or apart.

2. When magma reaches Earth's surface it becomes

• gas.
• steam.
• energy.
• lava.

3. Compared to rocks in Earth's crust, rocks in the mantle are more ________.

• dense
• mineral-rich
• granular
• porous

4. The pie section shows Earth's composition from the center to the surface. Section IV is MOST LIKELY composed of ______________.

• molten iron
• granitic rock
• solid iron
• basalt

5. A deep well or mine shaft goes through which layers of Earth?

• crust only
• mantle only
• crust and mantle
• mantle and core

6. A boundary where two tectonic plates come together, or collide, is called a (S6E5e)

• divergent boundary.
• convergent boundary.
• transform boundary
• transfer boundary

7. Earth's core is manly composed of (check all that apply)

• iron
• nickel
• aluminum
• silicon
• hydrogen

8. Earth's crust is manly composed of (check all that apply)

• aluminum
• silicon
• oxygen
• iron
• hydrogen

9. Earth's mantle is manly composed of (check all that apply)

• magnesium
• iron
• aluminum
• silicon
• hydrogen

10. What is the primary cause of volcanoes and earthquakes?

• crustal plate movement
• Earth's gravitational force
• higher than usual tides
• solar magnetic storms