1. slide 1 Do Now What would be the product if radon-222 underwent decay to produce 1) an alpha particle polonium-218 2) a beta particle francium-222 3) a gamma particle radon-222 4) a positron emission astatine-222

2. slide 2 Impact of Decay type atomic notation NpNp NnNn ZZ AA alpha ‒2‒2 ‒2‒2 ‒2‒2 ‒4‒4 beta +1 ‒1‒1 0 gamma 0000 positron ‒1‒1 +1 ‒1‒1 0

3. slide 3 Do Now What would be the product if radon-222 underwent decay to produce 1) an alpha particle polonium-218 2) a beta particle francium-222 3) a gamma particle radon-222 4) a positron emission astatine-222

4. slide 4 Do Now What would be the product if radon-222 underwent decay to produce 1) an alpha particle polonium-218 2) a beta particle francium-222 3) a gamma particle radon-222 4) a positron emission astatine-222

5. slide 5 Do Now What would be the product if radon-222 underwent decay to produce 1) an alpha particle polonium-218 2) a beta particle francium-222 3) a gamma particle radon-222 4) a positron emission astatine-222

6. slide 6 Do Now What would be the product if radon-222 underwent decay to produce 1) an alpha particle polonium-218 2) a beta particle francium-222 3) a gamma particle radon-222 4) a positron emission astatine-222

7. slide 7 Do Now What would be the product if radon-222 underwent decay to produce 1) an alpha particle polonium-218 2) a beta particle francium-222 3) a gamma particle radon-222 4) a positron emission astatine-222

8. slide 8 Nuclear Stability SWBAT explain the factors that influence nuclear stability, the characteristics of the band of stability, and predict the radioactive decay path of a nuclei based on these principles Write this in your notes

9. slide 9 Why Are Some Nuclei Radioactive? Some nuclei are radioactive Some nuclei are stable What factors determine this difference?

10. slide 10 Factors in Nuclear Stability 1)(n/p) ratio 2)odd or even N p and N n 3)atomic number Write this in your notes

11. slide 11 How does a nucleus stay together? Note: 1)A nucleus has multiple protons all very close to each other 2)Protons are positively charged 3)Like charges repel each other Why doesn't the nucleus blow apart? Strong Nuclear Force

12. slide 12 Strong Nuclear Force A force that acts on subatomic particles that are extremely close together The strongest of the four fundamental forces of the universe Write this in your notes

13. slide 13 Forces in the Nucleus Attraction The strong nuclear force attracts protons to protons, neutrons to neutrons, and protons to neutrons Repulsion The electromagnetic force cause like charges to repel each other Write this in your notes The stability of the nucleus partially depends on the balance between attractive strong nuclear force and repulsive electromagnetic force.

14. slide 14 1)Neutron to Proton Ratio A key factor in the stability of a nuclei is the neutron to proton ratio - the (n/p) ratio Each proton contributes to both repulsion and attraction in the nucleus Each neutron contributes to attraction only At low mass numbers, a 1.0 (n/p) ratio seems optimum for stability As the mass number rises, the optimum (n/p) ratio rises to 1.5 Write this in your notes

15. slide 15 Graph N p on x-axis Graph N n on y-axis A black point represents every stable nuclei All points lay between lines with slopes of 1.0 and 1.5 This collection of stable nuclei is known as the BAND OF STABILITY Write this in your notes

16. slide 16 2)Odd and Even N p and N n Having an even number of either protons or neutrons or both confers stability Stability believed to be derived from pairing of spin numbers number of stable nuclei NpNp NnNn % 148even 58% 53evenodd 40% 48oddeven 5odd 2% Total: 254 Write this in your notes

17. slide 17 The Stability Associated with Even N p & N n Creates Zig-Zag Shape

18. slide 18 3)Atomic Number All elements with atomic numbers greater than 83 are unstable and undergo spontaneous radioactive decay Write this in your notes

19. slide 19

20. slide 20 What does an unstable nuclei do? If a nuclei is unstable, it will undergo radioactive decay to make it more stable Each unstable nuclei will decay in a way that will address the source of instability If Z is too high

21. slide 21 What does an unstable nuclei do? If a nuclei is unstable, it will undergo radioactive decay to make it more stable Each unstable nuclei will decay in a way that will address the source of instability If Z is too high  lower Z

22. slide 22 What does an unstable nuclei do? If a nuclei is unstable, it will undergo radioactive decay to make it more stable Each unstable nuclei will decay in a way that will address the source of instability If Z is too high  lower Z If (n/p) is too high

23. slide 23 What does an unstable nuclei do? If a nuclei is unstable, it will undergo radioactive decay to make it more stable Each unstable nuclei will decay in a way that will address the source of instability If Z is too high  lower Z If (n/p) is too high  lower (n/p)

24. slide 24 What does an unstable nuclei do? If a nuclei is unstable, it will undergo radioactive decay to make it more stable Each unstable nuclei will decay in a way that will address the source of instability If Z is too high  lower Z If (n/p) is too high  lower (n/p) If (n/p) is too low

25. slide 25 What does an unstable nuclei do? If a nuclei is unstable, it will undergo radioactive decay to make it more stable Each unstable nuclei will decay in a way that will address the source of instability If Z is too high  lower Z If (n/p) is too high  lower (n/p) If (n/p) is too low  raise (n/p)

26. slide 26 Pathways to Nuclear Stability typeprocessΔpΔpΔnΔnimpact when utilized Write this in your notes

27. slide 27 Pathways to Nuclear Stability typeprocessΔpΔpΔnΔnimpact when utilized  decay ‒2‒2 ‒2‒2 Z fallsZ > 83 Write this in your notes

28. slide 28 Pathways to Nuclear Stability typeprocessΔpΔpΔnΔnimpact when utilized  decay ‒2‒2 ‒2‒2 Z fallsZ > 83  decay n  p + e ‒ +1 ‒1‒1 n/p fallshigh n/p Write this in your notes

29. slide 29 Pathways to Nuclear Stability typeprocessΔpΔpΔnΔnimpact when utilized  decay ‒2‒2 ‒2‒2 Z fallsZ > 83  decay n  p + e ‒ +1 ‒1‒1 n/p fallshigh n/p positron emission p  n + e + ‒1‒1 +1n/p riseslow n/p electron capture p + e ‒  n ‒1‒1 +1n/p riseslow n/p Write this in your notes

30. slide 30 Electron Capture Write this in your notes neutronprotonelectron ▬ Electron capture is a nuclear process to improve nuclear stability A proton from the nucleus "captures" an electron from the electron cloud. Together they become a neutron which remains in the nucleus. Nuclear impact is same as positron emission Opposite process from beta decay Not radioactive decay because no radiation is released

31. slide 31 Day 2 Intro

32. slide 32 Do Now Some unstable isotopes need to undergo a series of radioactive decays to reach a stable isotope. These are called "decay chains". For example, polonium-213 suffers  -decay, then  -decay, and then another  decay to reach a stable isotope. Determine the products of each step of this decay chain.

33. slide 33

34. slide 34 Impact of Decay type atomic notation NpNp NnNn ZZ AA alpha ‒2‒2 ‒2‒2 ‒2‒2 ‒4‒4 beta +1 ‒1‒1 0 gamma 0000 positron ‒1‒1 +1 ‒1‒1 0 REVIEW

35. slide 35 Forces in the Nucleus Attraction The strong nuclear force attracts protons to protons, neutrons to neutrons, and protons to neutrons Repulsion The electromagnetic force cause like charges to repel each other The stability of the nucleus partially depends on the balance between attractive strong nuclear force and repulsive electromagnetic force. REVIEW

36. slide 36 Factors in Nuclear Stability 1)(n/p) ratio 2)odd or even N p and N n 3)atomic number REVIEW

37. slide 37 Graph N p on x-axis Graph N n on y-axis A black point represents every stable nuclei All points lay between lines with slopes of 1.0 and 1.5 This collection of stable nuclei is known as the BAND OF STABILITY REVIEW

38. slide 38 2)Odd and Even N p and N n Having an even number of either protons or neutrons or both confers stability Stability believed to be derived from pairing of spin numbers number of stable nuclei NpNp NnNn 148even 53evenodd 48oddeven 5odd REVIEW

39. slide 39 REVIEW

40. slide 40 What does an unstable nuclei do? If a nuclei is unstable, it will undergo radioactive decay to make it more stable Each unstable nuclei will decay in a way that will address the source of instability If Z is too high  lower Z If (n/p) is too high  lower (n/p) If (n/p) is too low  raise (n/p) REVIEW

41. slide 41 Pathways to Nuclear Stability typeprocessΔpΔpΔnΔnimpact when utilized  decay ‒2‒2 ‒2‒2 Z fallsZ > 83  decay n  p + e ‒ +1 ‒1‒1 n/p fallshigh n/p positron emission p  n + e + ‒1‒1 +1n/p riseslow n/p electron capture p + e ‒  n ‒1‒1 +1n/p riseslow n/p REVIEW How Accurate Are These Predictions?

42. slide 42 Graphic Analysis of Predictions The band of stability is the red line.

43. slide 43 Too Many Neutrons Any atom above the red line will have a high n/p ratio These will be unstable and undergo a nuclear reaction to lower the n/p ratio Thus, any atom above the line should undergo beta decay  decay

44. slide 44 Too Many Protons Any atom below the red line will have a low n/p ratio These will be unstable and undergo a nuclear reaction to raise the n/p ratio Thus, any atom above the line should undergo positron emission or electron capture  + or e – capture

45. slide 45 Z is Too High Any atom with Z > 83 will have a Z value that is too high These will be unstable and undergo a nuclear reaction to lower Z Thus, any atom with Z > 83 should undergo alpha decay.  decay

46. slide 46 Predicted Decay Trends on Graph  decay  + or e – capture  decay

47. slide 47 PredictedObserved

48. slide 48 Predicted Decay Trends on Graph  decay  + or e – capture  decay Draw this in your notes

49. slide 49 Check For Understanding 1 Predict the decay pathway of hydrogen-3 1)Z = N p = 1 2)A = 3, N n = A - N p = 2 3)n/p = 2.0 (too high) 4)Need to lower n/p, so  -decay 5)helium-3 Write this in your notes

50. slide 50 Check For Understanding 2 Predict the decay pathway of plutonium-244 1)Z = N p = 94, Z > 83 2)Need to lower Z, so  -decay 3)uranium-240 4)or, n/p = 150/94 = 1.59 (too high) 5)need to lower n/p, so  -decay 6)americium-244 Write this in your notes

51. slide 51 Check For Understanding 3 Predict the decay pathway of nitrogen-13 1)Z = N p = 7 2)A = 13, N n = A - N p = 6 3)n/p = 0.86 (too low), need to raise n/p 4)positron emission or electron capture 5)carbon-13 Write this in your notes

52. slide 52 Pathways to Nuclear Stability typeprocessΔpΔpΔnΔnimpact when utilized  decay ‒2‒2 ‒2‒2 Z fallsZ > 83  decay n  p + e ‒ +1 ‒1‒1 n/p fallshigh n/p positron emission p  n + e + ‒1‒1 +1n/p riseslow n/p electron capture p + e ‒  n ‒1‒1 +1n/p riseslow n/p

53. slide 53 Independent Practice Predict the radioactive decay pathway 1)carbon-14 n/p = 1.3 (too high), reduce n,  -decay 2)radon-222 Z = 86 (Z>83), reduce p,  -decay 3)magnesium-22 n/p = 0.83 (too low), reduce p, positron emission 4)lead-214 n/p = 1.6 (too high), reduce n,  -decay

54. slide 54 Independent Practice Predict the radioactive decay pathway 1)carbon-14 n/p = 1.3 (too high), reduce n/p,  -decay 2)radon-222 Z = 86 (Z>83), reduce Z,  -decay, polonium-218 or n/p = 1.58 (too high), reduce n/p,  -decay, franconium-222 3)magnesium-22 n/p = 0.83 (too low), raise n/p, positron emission, sodium-22 4)lead-214 n/p = 1.6 (too high), reduce n/p,  -decay, bismuth-214

55. slide 55 Independent Practice Predict the radioactive decay pathway 1)carbon-14 n/p = 1.3 (too high), reduce n/p,  -decay 2)radon-222 Z = 86 (Z>83), reduce Z,  -decay, polonium-218 or n/p = 1.58 (too high), reduce n/p,  -decay, franconium-222 3)magnesium-22 n/p = 0.83 (too low), raise n/p, positron emission, sodium-22 4)lead-214 n/p = 1.6 (too high), reduce n/p,  -decay, bismuth-214

56. slide 56 Independent Practice Predict the radioactive decay pathway 1)carbon-14 n/p = 1.3 (too high), reduce n/p,  -decay 2)radon-222 Z = 86 (Z>83), reduce Z,  -decay, polonium-218 or n/p = 1.58 (too high), reduce n/p,  -decay, franconium-222 3)magnesium-22 n/p = 0.83 (too low), raise n/p, positron emission, sodium-22 4)lead-214 n/p = 1.6 (too high), reduce n/p,  -decay, bismuth-214

57. slide 57 Independent Practice Predict the radioactive decay pathway 1)carbon-14 n/p = 1.3 (too high), reduce n/p,  -decay 2)radon-222 Z = 86 (Z>83), reduce Z,  -decay, polonium-218 or n/p = 1.58 (too high), reduce n/p,  -decay, franconium-222 3)magnesium-22 n/p = 0.83 (too low), raise n/p, positron emission, sodium-22 4)lead-214 n/p = 1.6 (too high), reduce n/p,  -decay, bismuth-214

58. slide 58 Day 3 Intro

59. slide 59 Do Now What are the primary forces acting on the nucleus? How do they impact the particles in the nucleus and nuclear stability? What are the three factors used to estimate nuclear stability? What are the optimum values for these three factors?

60. slide 60 Particle Review 1 Below are two nuclear processes. A.How would each one change a nucleus? B.What is the name of each process? C.Under what circumstances would a nucleus want to undergo each process? –+ – + proton neutron electron positron

61. slide 61 Particle Review 2 – – + proton neutron electron positron Below are two nuclear processes. A.How would each one change a nucleus? B.What is the name of each process? C.Under what circumstances would a nucleus want to undergo each process?

62. slide 62 Analysis of Nuclear Stability Fluorine-16 is radioactive. 1)Analyze all 3 factors of stability & determine which need to be changed 2)Predict decay pathway and product 3)Reanalyzed the 3 factors of stability to determine if they are now acceptable

63. slide 63 Analysis of Nuclear Stability Fluorine-16 is radioactive. 1)Analyze all 3 factors of stability & determine which need to be changed 2)Predict decay pathway and product 3)Reanalyzed the 3 factors of stability to determine if they are now acceptable too low  N p : odd N n : odd  Z < 83

64. slide 64 Analysis of Nuclear Stability Fluorine-16 is radioactive. 1)Analyze all 3 factors of stability & determine which need to be changed 2)Predict decay pathway and product 3)Reanalyzed the 3 factors of stability to determine if they are now acceptable too low  N p : odd N n : odd  Z < 83 ++

65. slide 65 Analysis of Nuclear Stability Fluorine-16 is radioactive. 1)Analyze all 3 factors of stability & determine which need to be changed 2)Predict decay pathway and product 3)Reanalyzed the 3 factors of stability to determine if they are now acceptable too low  N p : odd N n : odd  Z < 83 N p : even N n : even Z < 83 ++

66. slide 66 Analysis of Nuclear Stability Boron-12 is radioactive. 1)Analyze all 3 factors of stability & determine which need to be changed 2)Predict decay pathway and product 3)Reanalyzed the 3 factors of stability to determine if they are now acceptable

67. slide 67 Analysis of Nuclear Stability Polonium-209 is radioactive. 1)Analyze all 3 factors of stability & determine which need to be changed 2)Predict decay pathway and product 3)Reanalyzed the 3 factors of stability to determine if they are now acceptable

68. slide 68 Backup Slides

69. slide 69 Check for Understanding BeforeAfter ResultsAnalysisResultAnalysis n67 p76 n/p ratio  odd/even p odd n even  p even n odd  Z< 83 < 83 Predict the decay pathway for nitrogen-13

70. slide 70 Check for Understanding BeforeAfter ResultsAnalysisResultAnalysis p12 n21 n/p ratio  odd/even p odd n even  p even n odd  Z< 83 < 83 Predict the decay pathway for hydrogen-3 

71. slide 71 Independent Practice BeforeAfter ResultsAnalysisResultAnalysis n87 p67 n/p ratio  odd/even p even n even p odd n odd  Z< 83 < 83 Predict the decay pathway for carbon-14

72. slide 72 Independent Practice BeforeAfter ResultsAnalysisResultAnalysis n127125 p8684 n/p ratio odd/even p even n odd  p even n odd  Z> 83   Predict the decay pathway for radon-222

73. slide 73 Review of Objective SWBAT explain the factors that influence nuclear stability, the characteristics of the band of stability, and predict the radioactive decay path of a nuclei based on these principles

74. slide 74 Pathways to Nuclear Stability typeprocessΔpΔpΔnΔnimpact when utilized  decay ‒2‒2 ‒2‒2 Z fallsZ > 83  decay n  p + e ‒ +1 ‒1‒1 n/p fallshigh N n positron emission p  n + e + ‒1‒1 +1n/p riseshigh N p electron capture p + e ‒  n ‒1‒1 +1n/p riseshigh N p

75. slide 75 Nuclei Decay to Become Stable

76. slide 76

77. slide 77 Outline 1 Why are some nuclei stable and others radioactive? Nuclear stability –What are the natural forces & what is strong nuclear force –balance between strong nuclear attraction & electrostatic repulsion –neutrons help stabilize because they contribute to strong nuclear attraction without contributing electrostatic repulsion

78. slide 78 Outline 2 Band of Stability –Lighter nuclei are stable with a (n/p) ratio of 1:1 –Heavier nuclei are stable with a (n/p) ratio of 1.5:1 –Even numbers of protons & neutrons are more stable –No nuclei with >83 protons is stable wrt radioactive decay Nuclei outside the band of stability want in –>2000 nuclei known, only 279 are stable –Above the band, get rid of some neutrons –Below the band, get rid of some protons –>83 protons, get rid of protons and neutrons

79. slide 79 Do Now Below are two nuclear processes. A.How would each one change a nucleus? B.What is the name of each process? C.Under what circumstances would a nucleus want to undergo each process?

80. slide 80 ‒ + neutron in the nucleus proton in the nucleus electron emitted

81. slide 81 Nuclei Decay to Become Stable

82. slide 82

83. slide 83 Decay Trends on Graph

84. slide 84

85. slide 85 Note The following examples have been chosen because their radioactive decay pathways are easily predicted It is often difficult to predict if a nuclei will be radioactive, and if so, its pathway of decay Often the instability of the nuclei is caused by a concert of multiple factors Radioactivity and radioactive decay pathways are usually determined experimentally