Eighth Grade Science
Earth’s History
Study Guide
1. What is a plate boundary?
2. What is continental crust made of?
3. What is oceanic crust made of?
4. Who proposed the theory of continental drift?
5. Why did scientists NOT support the theory of Continental Drift?
6. What is subduction?
7. The Earth’s plates are made of what layer(s)?
8. Explain convection currents.
9. What does convection mean?
10. What material forms the mid-ocean ridges?
11. Explain what type of plate movement is happening in each picture below. Then tell the NAME of
that plate boundary.
12. Which layer of the mantle is most flexible, often called soft and semi-rigid?
13. What is sea-floor spreading?
14. List the 3 pieces of evidence for Wegner’s theory of Continental Drift.
15. What does rifting mean and at what type of plate boundary does it happen?
16. What is Pangaea?
Eighth Grade Science
Earth’s History
Study Guide
17. List the layers of the Earth from most dense to least dense?
18. What layers of the Earth make up the lithosphere?
19. Label the layers of Earth in the picture below.
20. Which layer of the Earth is made up of liquid iron and nickel?
21. Which process is responsible for destroying rock/crust?
22. What do we call the chain of underwater mountains that are forming where sea-floor spreading is
occurring?
23. Consider the diagram below. Tell which type of plate boundaries are present in the diagram and
describe what is happening at each plate boundary.