FA30.2 - Nuclear Reactions

Get the formative assessment: FA30.2.docx

Get the reference for Isotopic Masses: IsotopicMass.pdf

Get more practice problems: Worksheet-ProblemsFrom30.2.docx

The formative assessment solved:

1. What is the binding energy and the binding energy per nucleon of Ca-44?

(381.0 MeV, 8.658 MeV/nucleon)

More examples:

Binding Energy Example 1

Binding Energy Example 2

2. Fill in the table (not all these reactions occur)

Watch these videos to grade your FA:

More examples:

Balancing Nuclear Reactions Example 1

Balancing Nuclear Reactions Example 2

Balancing Nuclear Reactions Example 3

Balancing Nuclear Reactions Example 4

Balancing Nuclear Reactions Example 5

3. Find the Q value for this nuclear reaction: ⁷₃Li(t,n)⁹₄Be. Label the reaction as either energy requiring (endoergic) or energy releasing (exoergic) (you will have to look up the masses in the table...)

(Exoergic Q = +10.44 MeV)

More examples:

Q Value Example 1

Q Value Example 2

4-5. Consider this fission reaction: ²³⁵₉₂U + ¹₀n = ¹⁴⁸₅₇La + ⁸⁵₃₅Br + some neutrons

U-235 = 235.043923 u, La-148 = 147.932191 u, Br-85 = 84.915608 u (These masses will be given to you here)

4. How many neutrons are released?

(3)

5. What is the Q value for this reaction?

(166.5 MeV - your answer should have 4 sig figs)

More Practice Problems: Get this worksheet

Problems from 30.2 - Nuclear Reactions - (you will get a table of neutral atom masses)

Binding Energy:

¹₁H = 1.007825 u

1. Find the binding energy and the binding energy per nucleon of Helium-4 (28.30 MeV, 7.074 MeV) <Video>

2. Find the binding energy and binding energy per nucleon of Fluorine-19. (147.8 MeV, 7.779 MeV) <Video>

3. Find the binding energy and binding energy per nucleon of Silicone-28. (236.5 MeV, 8.448 MeV) <Video>

4. Find the binding energy and binding energy per nucleon of Argon-36. (306.7 MeV, 8.520 MeV) <Video>

5. Find the binding energy and binding energy per nucleon of Chromium-52. (456.3 MeV, 8.776 MeV) <Video>

6. Balancing Nuclear Reactions: Find the missing nucleus: d = deuterium, t = tritium

Finding the Q value: Find the Q value for the following reactions. Label the reaction as either energy requiring, (endoergic) or energy releasing (exoergic). You will need to look up the masses in a table.

7. ⁷₃Li(p,α)⁴₂He. (Exo, Q = 17.35 MeV) <Video>

8. ⁶₃Li(n,α)³₁H. (Exo, Q = +4.783 MeV). <Video>

9. ⁷₃Li(α, n)¹⁰₅B. (Endo, Q = -2.790 MeV). <Video>

10. ¹²₆C(t,n)¹⁴₇N. (Exo, Q = 4.015 MeV). <Video>

11. ¹⁴₇N(α,p)¹⁷₈O. (Endo, Q = -1.192 MeV). <Video>

Fission Reactions: For each of the following (fictitious) fission reactions, determine the number of free neutrons liberated, and the Q value of the reaction as a whole:

12. ²³⁵₉₂U + ¹₀n ® ¹⁴¹₅₆Ba + ⁹⁰₃₆Kr + some neutrons. <Video>

U-235 = 235.043923 u, Ba-141 = 140.914406 u, Kr-90 = 89.919524 u (5 neutrons, Q = +163.3 MeV)

13. ²³⁵₉₂U + ¹₀n ® ¹³⁸₅₅Cs + ⁹²₃₇Rb + some neutrons. <Video>

U-235 = 235.043923 u, Cs-138 = 137.911011 u, Rb-92 = 91.919725 u (6 neutrons, Q = +158.2 MeV)

14. ²³⁵₉₂U + ¹₀n ® ¹³⁷₅₄Xe + ⁹⁵₃₈Sr + some neutrons. <Video>

U-235 = 235.043923 u, Xe-137 = 136.911563 u, Sr-95 = 94.919358 u (4 neutrons, Q = +174.2 MeV)

15. ²³⁵₉₂U + ¹₀n ® ¹²⁶₄₈Cd + ¹⁰⁷₄₄Ru + some neutrons. <Video>

U-235 = 235.043923 u, Cd-126 = 125.922354 u, Ru-107 = 106.909907 u (3 neutrons, Q = +181.0 MeV)

16. ²³⁵₉₂U + ¹₀n ® ¹²⁶₄₉In + ¹⁰⁸₄₃Tc + some neutrons. <Video>

U-235 = 235.043923 u, In-126 = 125.916465 u, Tc-108 = 107.918480 u (2 neutrons, Q = +186.6 MeV)

The instruction for this unit: