Chapter 10, Section 1-5

1. Chapter 10, Section 1-5

3. Question 1 - 10 • are the preserved remains or traces of living things.

4. Answer 1 – 10 • fossils

5. Question 1 - 20 • Fossils provide evidence of

6. Answer 1 – 20 • how life has changed over time

7. Question 1 - 30 • a hollow area in sediment in the shape of or part of an organism.

8. Answer 1 – 30 • mold

9. Question 1 - 40 • evidence of the history of life and past environments on Earth is called

10. Answer 1 – 40 • The fossil record

11. Question 1 - 50 • List the steps of how fossils are most commonly formed

12. Answer 1 – 50 • Organism dies • Organism is buried by sediment • Sediment hardens and preserves fossil

13. Question 2 - 10 • The number of years since the rock formed

14. Answer 2 – 10 • absolute age

15. Question 2 - 20 • In horizontal sedimentary rocks, the oldest layer is at the bottom and the newest layer is on the top and determines the relative ages of rocks

16. Answer 2 – 20 • The Law of Superposition

17. Question 2 - 30 • the surface where new rock meets up with a much older rock surface.

18. Answer 2 – 30 • Unconformity

19. Question 2 - 40 • What is an index fossil?

20. Answer 2 – 40 • A fossil that is widely distributedand representsa type of organism that only existedbriefly

21. Question 2 - 50 • Index fossils are useful because-

22. Answer 2 – 50 • tell the relative ages of rock layers by how they occur

23. Question 3 - 10 • As elements break down over time they release particles and energy in a process called

24. Answer 3 – 10 • radioactive decay

25. Question 3 - 20 • How fast or slow the radioactive elements decay is always constant (never changing) and the rate of decay is called

26. Answer 3 – 20 • half-life

27. Question 3 - 30 • Very useful in dating rocks because it has a long half-life

28. Answer 3 – 30 • Potassium-Argon Dating

29. Question 3 - 40 • When carbon-14 is left in an organism, scientists measure this amount that is left to find absolute age. Is the carbon-14 the radioactive element or the new element formed?

30. Answer 3 – 40 • radioactive

31. Question 3 - 50 • Why is Radioactive dating is good for igneous rocks but not sedimentary rocks

32. Answer 3 – 50 • Scientists can date particles but not layers in sedimentary rocks. • Scientists can only date solid rocks.

33. Question 4 - 10 • a record of the life forms and geologic events in Earth’s history

34. Answer 4 – 10 • geological time scale

35. Question 4 - 20 • After Precambrian Time, basic units of the GTS are

36. Answer 4 – 20 • eras and periods

37. Question 4 - 30 • three long units of time from Precambrian Time to the present, Ex: The Paleozoic, Mesozoic, and Cenozoic

38. Answer 4 – 30 • Eras

39. Question 4 - 40 • Later, _________________________determined absolute age of divisions in the GTS

40. Answer 4 – 40 • radioactive dating

41. Question 4 - 50 • What happened during the Precambrian time period?

42. Answer 4 – 50 • 1st oceans, atmospheres, landforms, and single-celled organisms.

43. Question 5 - 10 • Scientists hypothesize that the Earth formed at the same time as other planets and the sun at what time?

44. Answer 5 – 10 • about 4.6 billion years ago

45. Question 5 - 20 • Earth started as a ball of

46. Answer 5 – 20 • dust, rock, and ice in space

47. Question 5 - 30 • As Earth cooled, water vapor condensed forming rain, accumulating to form

48. Answer 5 – 30 • The oceans

49. Question 5 - 40 • Without earth’s earliest life forms we would have no…

50. Answer 5 – 40 • Oxygen/ozone