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2. Standardized Test Prep Image and Math Focus Bank
Resources
Chapter Presentation
Bellringers
Transparencies
Standardized Test Prep
Image and Math Focus Bank
Visual Concepts

3. Chapter L4 Table of Contents Section 1 Radioactivity
Atomic Energy
Table of Contents
Section 1 Radioactivity
Section 2 Energy from the Nucleus

4. Chapter L4
Section 1 Radioactivity
Bellringer
In your science journal write a few sentences about the term nuclear radiation. Include what you know about nuclear radiation, any benefits, and any dangers you can think of. For example, when is radiation used to help people? When is radiation harmful?

5. Chapter L4 Objectives Describe how radioactivity was discovered.
Section 1 Radioactivity
Objectives
Describe how radioactivity was discovered.
Compare alpha, beta, and gamma decay.
Describe the penetrating power of the three kinds of nuclear radiation.
Calculate ages of objects using half-life.
Identify uses of radioactive materials.

6. Discovering Radioactivity
Chapter L4
Section 1 Radioactivity
Discovering Radioactivity
An Unexpected Result Henri Becquerel discovered that radium gave off a form of radiation.
Naming the Unexpected Marie Curie, a scientist working with Becquerel, named the process by which some nuclei give off nuclear radiation. She named the process radioactivity, which is also called radioactive decay.

7. Kinds of Radioactive Decay
Chapter L4
Section 1 Radioactivity
Kinds of Radioactive Decay
Alpha Decay The release of an alpha particle from a nucleus is called alpha decay. An alpha particle is made up of two protons and two neutrons.
Conservation in Decay In radioactive decay, the mass number is conserved, and the charge is conserved.
Beta Decay The release of a beta particle from a nucleus is called beta decay. A beta particle can be an electron or a positron.

8. Chapter L4
Section 1 Radioactivity

9. Kinds of Radioactive Decay, continued
Chapter L4
Section 1 Radioactivity
Kinds of Radioactive Decay, continued
Two Types of Beta Decay A carbon-14 nucleus undergoes beta decay. During this kind of decay, a neutron breaks into a proton and an electron. Not all isotopes of an element decay in the same way. A carbon-11 nucleus undergoes beta decay when a proton breaks into a positron and a neutron.
Gamma Decay Energy is also given off during alpha decay and beta decay. Some of this energy is in the form of light that has very high energy called gamma rays.

10. The Penetrating Power of Radiation
Chapter L4
Section 1 Radioactivity
The Penetrating Power of Radiation
Effects of Radiation on Matter Atoms that are hit by nuclear radiation can give up electrons. Chemical bonds between atoms can break when hit by nuclear radiation.
Damage to Living Matter When an organism absorbs radiation, its cells can be damaged. A single large exposure to radiation can lead to radiation sickness.

11. The Penetrating Power of Radiation, continued
Chapter L4
Section 1 Radioactivity
The Penetrating Power of Radiation, continued
Damage to Nonliving Matter Radiation can also damage nonliving matter. When metal atoms lose electrons, the metal is weakened.
Damage at Different Depths Gamma rays go through matter easily. They can cause damage deep within matter. The penetrating powers of different forms of radiation can be seen on the next slide.

12. Chapter L4
Section 1 Radioactivity

13. Chapter L4 Finding a Date by Decay
Section 1 Radioactivity
Finding a Date by Decay
Carbon-14—It’s in You! During an organism’s life, the percentage of carbon-14 in the organism stays about the same. But when an organism dies, over time the level of carbon-14 in the remains drops because of radioactive decay.
A Steady Rate of Decay A half-life is the amount of time it takes one-half of the nuclei of a radioactive isotope to decay. The next slide models this process.

14. Chapter L4
Section 1 Radioactivity

15. Finding a Date by Decay, continued
Chapter L4
Section 1 Radioactivity
Finding a Date by Decay, continued
Determining Age Carbon-14 can be used to find the age of objects up to 50,000 years old. To find the age of older things, other elements must be used.

16. Chapter L4 Uses of Radioactivity
Section 1 Radioactivity
Uses of Radioactivity
Radioactivity in Healthcare Doctors use tracers to help diagnose medical problems. Radioactive tracers that have short half-lives are fed to or injected into a patient. Then, a detector is used to follow the tracer as it moves through the body.
Radioactivity in Industry Radioactive isotopes can also help detect defects in structures. Some space probes have been powered by radioactive materials.

17. Chapter L4 Radioactive Tracer Section 1 Radioactivity
Click below to watch the Visual Concept.
You may stop the video at any time by pressing the Esc key.
Visual Concept

18. Chapter L4
Section 2 Energy from the Nucleus
Bellringer
Define each of the following terms in your own words in your science journal:
fission
fusion
Are the terms opposites, or are they similar? How is energy involved in each? Discuss your ideas with the group.

19. Chapter L4 Objectives Describe nuclear fission.
Section 2 Energy from the Nucleus
Objectives
Describe nuclear fission.
Identify advantages and disadvantages of fission.
Describe nuclear fusion.
Identify advantages and disadvantages of fusion.

20. Chapter L4 Nuclear Fission
Section 2 Energy from the Nucleus
Nuclear Fission
Nuclear Fission is the process by which a large nucleus splits into two small nuclei and releases energy.
Energy from Matter The nuclear fission of the uranium nuclei in one fuel pellet releases as much energy as the chemical change of burning about 1,000 kg of coal. The nuclear fission of uranium-235 is shown on the next slide.

21. Chapter L4
Section 2 Energy from the Nucleus

22. Nuclear Fission, continued
Chapter L4
Section 2 Energy from the Nucleus
Nuclear Fission, continued
Nuclear Chain Reactions A nuclear chain reaction is a continuous series of nuclear fission reactions.

23. Nuclear Fission, continued
Chapter L4
Section 2 Energy from the Nucleus
Nuclear Fission, continued
Energy from a Chain Reaction Nuclear power plants use controlled chain reactions. The energy released from the nuclei in the uranium fuel within the nuclear power plants is used to generate electrical energy. The next slide shows how a nuclear power plant works.

24. Chapter L4
Section 2 Energy from the Nucleus

25. Advantages and Disadvantages of Fission
Chapter L4
Section 2 Energy from the Nucleus
Advantages and Disadvantages of Fission
Accidents A concern that many people have about nuclear power is the risk of an accident.
What Waste! Controlled fission has been carried out for only about 50 years. But the waste will give off high levels of radiation for thousands of years.
Nuclear Versus Fossil Fuel Nuclear power plants cost more to build than power plants that use fossil fuels, but often cost less to run than plants that use fossil fuels because less fuel is needed.

26. Chapter L4 Nuclear Fusion
Section 2 Energy from the Nucleus
Nuclear Fusion
What Is Nuclear Fusion? In nuclear fusion, two or more nuclei that have small masses combine, or fuse, to form a larger nucleus.
Plasma Needed In order for fusion to happen, the repulsion between positively charged nuclei must be overcome. Very high temperatures are needed—more than 100,000,000 °C! At these high temperatures, matter is a plasma.

27. Advantages and Disadvantages of Fusion
Chapter L4
Section 2 Energy from the Nucleus
Advantages and Disadvantages of Fusion
Less Accident Prone The concern about an accident such as the one at Chernobyl is much lower for fusion reactors.
Oceans of Fuel Scientists studying fusion use hydrogen-2 and hydrogen-3 in their work. Hydrogen-1 is much more common than these isotopes. But there is enough of them in Earth’s waters to provide fuel for millions of years.

28. Advantages and Disadvantages of Fusion, continued
Chapter L4
Section 2 Energy from the Nucleus
Advantages and Disadvantages of Fusion, continued
Less Waste The products of fusion reactions are not radioactive. So, fusion is a “cleaner” source of energy than fission is.

29. Chapter L4
Atomic Energy
Concept Map
Use the terms below to complete the concept map on the next slide.
alpha particle
mass number
nuclei
nuclear fusion
gamma ray
radioactive decay
nuclear fission
atomic nucleus

30. Chapter L4
Atomic Energy

31. Chapter L4
Atomic Energy

32. End of Chapter L4 Show

33. Chapter L4
Standardized Test Preparation
Reading
Read each of the passages. Then, answer the questions that follow each passage.

34. Chapter L4
Standardized Test Preparation
Passage 1 Have you noticed that your forks, knives, and spoons don’t tarnish easily? Most metal utensils are made of stainless steel. Because it doesn’t tarnish, stainless steel is also used in nuclear reactors. Some scientists study radiation’s effects on metals and other substances. An important focus of their studies is radiation’s effect on the structure of stainless steel. The damage to stainless steel is caused mainly by neutron and heavy ion radiation inside nuclear reactors.
Continued on the next slide

35. Chapter L4
Standardized Test Preparation
Passage 1, continued The radiation causes stress in the metal. The stress leads to corrosion and finally to cracking. Clearly, this feature is not desirable in parts of a nuclear reactor! Scientists hope that by studying the way radiation affects the atoms of metals, they can find a way to use the incoming radiation to make the surface stronger instead of weaker.

36. Chapter L4
Standardized Test Preparation
1. Which of the following happens last as stainless steel is damaged in a nuclear reactor?
A The steel corrodes.
B The steel is exposed to radiation.
C The steel cracks.
D The steel is stressed.

37. Chapter L4
Standardized Test Preparation
1. Which of the following happens last as stainless steel is damaged in a nuclear reactor?
A The steel corrodes.
B The steel is exposed to radiation.
C The steel cracks.
D The steel is stressed.

38. Chapter L4 2. Which of the following is a goal of the scientists?
Standardized Test Preparation
2. Which of the following is a goal of the scientists?
F to use radiation to strengthen stainless steel
G to keep stainless steel from tarnishing
H to keep spoons and forks from cracking
I to prevent stainless steel from absorbing radiation

39. Chapter L4 2. Which of the following is a goal of the scientists?
Standardized Test Preparation
2. Which of the following is a goal of the scientists?
F to use radiation to strengthen stainless steel
G to keep stainless steel from tarnishing
H to keep spoons and forks from cracking
I to prevent stainless steel from absorbing radiation

40. Chapter L4
Standardized Test Preparation
3. Why is stainless steel a good metal to use in a nuclear reactor?
A It is made stronger by radiation.
B It does not tarnish easily.
C It cracks under stress.
D It is not affected by radiation.

41. Chapter L4
Standardized Test Preparation
3. Why is stainless steel a good metal to use in a nuclear reactor?
A It is made stronger by radiation.
B It does not tarnish easily.
C It cracks under stress.
D It is not affected by radiation.

42. Chapter L4
Standardized Test Preparation
Passage 2 A space probe takes about 7 years to reach Saturn. What could supply energy for the cameras and equipment after that time in space? The answer is the radioactive element plutonium! The nuclei (singular, nucleus) of plutonium atoms are radioactive, so the nuclei are unstable. They become stable by giving off radiation in the form of particles and rays. This process heats the materials surrounding the plutonium, and the thermal energy of the materials is converted into electrical energy by a radioisotope thermoelectric generator (RTG).
Continued on the next slide

43. Chapter L4 Passage 2, continued Spacecraft such as
Standardized Test Preparation
Passage 2, continued Spacecraft such as
Voyager, Galileo, and Ulysses depended on RTGs for electrical energy. Because an RTG can generate electrical energy for 10 or more years by using one sample of plutonium, an RTG provides energy longer than any battery can. In fact, the RTGs on Voyager were still providing energy after 20 years!

44. Chapter L4
Standardized Test Preparation
1. Plutonium in an RTG can be expected to provide energy for how long?
A much less than 7 years
B about 7 years
C 10 years or more
D 20 years

45. Chapter L4
Standardized Test Preparation
1. Plutonium in an RTG can be expected to provide energy for how long?
A much less than 7 years
B about 7 years
C 10 years or more
D 20 years

46. Chapter L4
Standardized Test Preparation
2. Which of the following terms has the most similar meaning to the term radioactive?
F thermoelectric
G plutonium
H radiation
I unstable

47. Chapter L4
Standardized Test Preparation
2. Which of the following terms has the most similar meaning to the term radioactive?
F thermoelectric
G plutonium
H radiation
I unstable

48. Chapter L4 3. What is the final form of energy provided by RTGs?
Standardized Test Preparation
3. What is the final form of energy provided by RTGs?
A thermal
B electrical
C particles and rays
D nuclear

49. Chapter L4 3. What is the final form of energy provided by RTGs?
Standardized Test Preparation
3. What is the final form of energy provided by RTGs?
A thermal
B electrical
C particles and rays
D nuclear

50. Interpreting Graphics
Chapter L4
Standardized Test Preparation
Interpreting Graphics
The table below shows the half-lives of some radioactive isotopes. Use the table below to answer the questions that follow.

51. Chapter L4
Standardized Test Preparation
1. Half of a sample of which of the following isotopes would take the longest to decay?
A uranium-238
B hydrogen-3
C polonium-210
D calcium-36

52. Chapter L4
Standardized Test Preparation
1. Half of a sample of which of the following isotopes would take the longest to decay?
A uranium-238
B hydrogen-3
C polonium-210
D calcium-36

53. Chapter L4
Standardized Test Preparation
2. How old is an artifact if only one-fourth of the hydrogen-3 in the sample remains?
F years
G 6.15 years
H 12.3 years
I 24.6 years

54. Chapter L4
Standardized Test Preparation
2. How old is an artifact if only one-fourth of the hydrogen-3 in the sample remains?
F years
G 6.15 years
H 12.3 years
I 24.6 years

55. Chapter L4
Standardized Test Preparation
3. How many days will it take for three-fourths of a sample of radioactive polonium-210 to decay?
A 69 days
B days
C 138 days
D 276 days

56. Chapter L4
Standardized Test Preparation
3. How many days will it take for three-fourths of a sample of radioactive polonium-210 to decay?
A 69 days
B days
C 138 days
D 276 days

57. Chapter L4
Standardized Test Preparation
4. How many isotopes have shorter half-lives than polonium-210?
F two
G three
H four
I five

58. Chapter L4
Standardized Test Preparation
4. How many isotopes have shorter half-lives than polonium-210?
F two
G three
H four
I five

59. Chapter L4 Math Read each question, and choose the best answer.
Standardized Test Preparation
Math
Read each question, and choose the best answer.

60. Chapter L4
Standardized Test Preparation
1. The Butterfly Society spent 1.5 h planting a butterfly garden on Saturday and twice as many hours on Sunday. Which equation could be used to find the total number of hours they spent planting on those 2 days?
A n  2(1.5)
B n  1.5  2(1.5)
C n  1.5  1.5  2
D n  2  2  1.5

61. Chapter L4
Standardized Test Preparation
1. The Butterfly Society spent 1.5 h planting a butterfly garden on Saturday and twice as many hours on Sunday. Which equation could be used to find the total number of hours they spent planting on those 2 days?
A n  2(1.5)
B n  1.5  2(1.5)
C n  1.5  1.5  2
D n  2  2  1.5

62. Chapter L4
Standardized Test Preparation
2. How many half-lives have passed if one-eighth of a sample of radioactive carbon-14 remains?
F two
G three
H four
I eight

63. Chapter L4
Standardized Test Preparation
2. How many half-lives have passed if one-eighth of a sample of radioactive carbon-14 remains?
F two
G three
H four
I eight

64. Chapter L4
Standardized Test Preparation
3. Which of the following shows the correct fraction of the original sample of radioactive isotope that remains after four half-lives?
A 4(1/2)
B (1/2)(1/4)
C 4 1/2
D (1/2)(1/2)(1/2)(1/2)

65. Chapter L4
Standardized Test Preparation
3. Which of the following shows the correct fraction of the original sample of radioactive isotope that remains after four half-lives?
A 4(1/2)
B (1/2)(1/4)
C 4 1/2
D (1/2)(1/2)(1/2)(1/2)

66. Chapter L4
Standardized Test Preparation
4. To find the area of a circle, use the equation area  r2. If the radius of circle A is doubled, how will the area of the circle change?
F The area will be 1/4 as large.
G The area will be 1/2 as large.
H The area will be 2 times larger.
I The area will be 4 times larger.

67. Chapter L4
Standardized Test Preparation
4. To find the area of a circle, use the equation area  r2. If the radius of circle A is doubled, how will the area of the circle change?
F The area will be 1/4 as large.
G The area will be 1/2 as large.
H The area will be 2 times larger.
I The area will be 4 times larger.

68. Chapter L4
Section 1 Radioactivity

69. Chapter L4
Section 2 Energy from the Nucleus

70. Chapter L4
Standardized Test Preparation

71. Chapter L4
Standardized Test Preparation