Name: ______________________________ Date:___________ Period: _____ Bin# ___
8th Grade Science Test 3 – Earth Science Study Guide
Ongoing science skills and techniques review:
1. What tool would you use to find the mass of an object?
2. What tool would you use to find the volume of an object?
3. What tool would you use to find the length of an object?
4. What does a line graph show?
5. What does the Y – Axis represent? X- Axis?
6. How many meters are in 16.3 km?
7. Why do we use dimensional analysis?
8. How many significant figures are in 6.305?
9. How many significant figures are in 000.7850?
LT 1. Explain what fossils are and how most fossils form
10. Most rocks that form from fragmental rock particles are classified as
____________ rocks.
11. What type of rock are Stromatolites found in?
LT 2. Identify and describe different types of fossils
12. Describe preserved remains.
13. Describe what a petrified fossil is.
14. Describe what a trace fossil is.
15. What is the difference between a mold and a cast fossil?
LT 3. Describe several ways that scientist determine the relative age of fossils
16. What is relative age?
17. How do scientists use relative age to date rocks?
LT 4. Describe how geologists use index fossils to date rocks.
18. What are index fossils? Give an example of an index fossil.
The diagrams show the index fossils found in rock layers in at least two different
locations. Use the diagram to answer questions 19 – 22.
19. According to the law of superposition, the oldest rock layers at site 1 and 2 are
layers
20. The youngest rock layer at each location is layers
21. What are the index fossils for the layers B and W?
22. Layer F at site 1 and Layer Y at site 2 both contain the fossils for dinosaurs and
plants. What can these index fossils tell us about the period in which they were
formed?
Name: ______________________________ Date:___________ Period: _____ Bin# ___
LT 5. Explain the law of superposition.
23. Explain the law of superposition
LT 6. Describe the process of radioactive decay
24. Describe the process of radioactive decay.
25. What is the half-life of an element?
26. What are the two types of radioactive dating?
LT 7. Explain how the absolute age of a rock can be determined using radioactive
dating.
27. Which radioactive element is used to determine the absolute age of late Permian
(260million years ago) period animal?
Radioactive Decay of Potassium-40
Time gone by (in billions of years)
28. When the rock first forms, what is the percent of potassium-40
compared with the percent of argon-40?
29. What is the half-life of potassium-40?
30. What are the percentages of the two elements at 1.3 billion years?
31. After the first 1.3 billion years, does the rock contain more potassium40 or argon-40?
32. What are the percentages of the two elements after three half-lives of
potassium-40?
33. Does a geologist have to wait 1.3 billion years before seeing a
difference in the amounts of these two elements? Explain.
LT 8. Describe the characteristics of the Earth's interior.
34. Describe the crust.
35. Describe the mantle.
36. Describe the inner core.
37. Explain how heat is transferred.
LT 9. Identify what causes convection currents.
38. What causes convection currents in the Earth? 39. How does the material in the mantel move?
Name: ______________________________ Date:___________ Period: _____ Bin# ___
LT 10. Recall the causes of earthquakes and volcanoes and how they change the
surface of the Earth in a short period of time.
40. What causes “hot spot” volcanoes to form?
41. Where do most volcanoes occur on Earth surface?
42. What are geysers?
43. What is the force that causes magma to erupt at the surface of the Earth?
LT 11. Recall how Earth's plates move and change the surface of the Earth over long
periods of time.
44. What happens when two plates collide with each other?
45. What theory do geologists believe is the driving force behind plate tectonics?