2. Review Atomic Number (Z) – number of protons
Mass Number (A) – sum of protons and neutrons
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3. 4 Forces in Nature Force Equation notes Gravity F = G m1 m2/r2
Works at an infinite distance. Weakest of all forces.
Electromagnetic
F = K q1 q2/r2
Works for short distances, Holds the atom together.
Strong Nuclear force
E =mc2 (mass defect)
This is the glue that holds the nucleus together.
Weak nuclear force
The force responsible for radioactivity. Pulls the nucleus apart.

4. No nucleus beyond lead is stable indefinitely.
Stable nuclei
When the strong force is greater than the weak force the nucleus is stable.
No nucleus beyond lead is stable indefinitely.
Iron has the most stable nuclei.
Most atoms have examples of stable and unstable nuclei

5. The Zone of Stability
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6. Unstable nuclei become stable by changing the make up of their nucleus
When the weak force is greater than the strong force the nucleus is unstable.
Unstable nuclei become stable by changing the make up of their nucleus
This process is known as radioactive decay.

7. Radioactive Stability
Nuclides with 84 or more protons are unstable.
Light nuclides are stable when Z equals A – Z (neutron/proton ratio is 1).
For heavier elements the neutron/proton ratio required for stability is greater than 1 and increases with Z.
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8. Radioactive Stability
Certain combinations of protons and neutrons seem to confer special stability.
Even numbers of protons and neutrons are more often stable than those with odd numbers.
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9. Radioactive Stability
Certain specific numbers of protons or neutrons produce especially stable nuclides.
2, 8, 20, 28, 50, 82, and 126
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10. Types of Radioactive Decay
Alpha production (α):
Beta production (β):
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11. Types of Radioactive Decay
Gamma ray production (γ):
Positron production:
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12. Types of Radioactive Decay
Electron capture:
Inner-orbital electron
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13. Decay Series (Series of Alpha and Beta Decays)
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14. Which of the following produces a particle? electron capture positron
CONCEPT CHECK!
Which of the following produces a particle?
electron capture
positron
alpha particle
beta particle
The correct answer is d. Go through the rest of the equations to identify these types of equations as well.
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15. Rate of Decay
Rate = kN
The rate of decay is proportional to the number of nuclides. This represents a first-order process.
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16. Half-Life
Time required for the number of nuclides to reach half the original value.
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17. Nuclear Particles To play movie you must be in Slide Show Mode
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18. Half-Life of Nuclear Decay
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19. EXERCISE!
A first order reaction is 35% complete at the end of 55 minutes. What is the value of k?
k = 7.8 × 10-3 min-1
k = 7.8 x 10-3 min-1. If students use [A] = 35 in the integrated rate law (instead of 65), they will get k = 1.9 x 10-2 min-1.
Note: Use the red box animation to assist in explaining how to solve the problem.

20. Nuclear Transformation
The change of one element into another.
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21. A Schematic Diagram of a Cyclotron

22. A Schematic Diagram of a Linear Accelerator
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23. Measuring Radioactivity Levels
Geiger counter
Scintillation counter
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24. Geiger Counter To play movie you must be in Slide Show Mode
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25. Carbon–14 Dating Used to date wood and cloth artifacts.
Based on carbon–14 to carbon–12 ratio.
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26. Radiotracers
Radioactive nuclides that are introduced into organisms in food or drugs and whose pathways can be traced by monitoring their radioactivity.
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27. Radiotracers
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28. Energy and Mass
When a system gains or loses energy it also gains or loses a quantity of mass.
E = mc2
Δm = mass defect
ΔE = change in energy
If ΔE is negative (exothermic), mass is lost from the system.
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29. Mass Defect (Δm) Calculating the mass defect for :
Since atomic masses include the masses of the electrons, we must account for the electron mass.
nucleus is “synthesized” from 2 protons and two neutrons.

30. Binding Energy
The energy required to decompose the nucleus into its components.
Iron-56 is the most stable nucleus and has a binding energy of 8.79 MeV.
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31. Binding Energy per Nucleon vs. Mass Number
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32. Nuclear Fission and Fusion
Fusion – Combining two light nuclei to form a heavier, more stable nucleus.
Fission – Splitting a heavy nucleus into two nuclei with smaller mass numbers.
Bombardment+ Parent Daughters + neutrons
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33. Nuclear Fission To play movie you must be in Slide Show Mode
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34. Criterion for a self sustaining reaction:
The target nuclei must produce at least one neutrons upon splitting.
The must be sufficient mass of target nuclei for the reaction to continue.
The mass defect must be sufficient in order to produce high energy emissions.

35. Fission Processes
A self-sustaining fission process is called a chain reaction.
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36. Schematic Diagram of a Nuclear Power Plant
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37. Schematic Diagram of a Reactor Core
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38. Fuel rods: Contains fissionable material
What does each part do?
Fuel rods: Contains fissionable material
Control Rods: Conic neutron “catchers” made of boron or cadmium
Heat exchanger: Web of pipes containing superheated fluid that boils the water
Reactor vessel: Contains reactor core
Containment fluid: Fluid that surrounds fissionable material also serves to control reaction
Turbine: Spins when steam passes through

39. Condenser: Returns steam to water.
More parts
Generator: Connected to turbine. Converts mechanical Energy to electrical
Condenser: Returns steam to water.
External water source: Provides water for condenser.
Cooling tower: Releases excess heat so water can be returned to ecosystem
Pumps: Move fluid around and create elevated pressure conditions

40. Nuclear Waste
Low Level
High level

41. Nuclear Energy?
Pros
Cons

42. Nuclear Fusion To play movie you must be in Slide Show Mode
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43. Biological Effects of Radiation
Depend on:
Energy of the radiation
Penetrating ability of the radiation
Ionizing ability of the radiation
Chemical properties of the radiation source
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44. rem (roentgen equivalent for man)
The energy dose of the radiation and its effectiveness in causing biologic damage must be taken into account.
Number of rems = (number of rads) × RBE
rads = radiation absorbed dose
RBE = relative effectiveness of the radiation in causing biologic damage

45. Effects of Short-Term Exposures to Radiation
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