1. Nuclear Physics
Developed by Mr. D. Patterson

2. Outcomes
explain and apply the concepts of mass defect and binding energy of nuclides—this will include applying the relationships:
Use conversion that 1 u of mass is equivalent to 931 MeV of energy

3. WINNER! Binding Energy Electromagnetic forces push protons apart
Strong nuclear forces pull nucleons together
WINNER!

4. Binding Energy Energy is required to break apart a nucleus
The binding energy is the amount of energy required to break apart a nucleus
Energy

5. Binding Energy

6. Binding Energy
Individual nucleons have more mass than the same number of nucleons bound as a nucleus.
Nucleons bound together as a nucleus have a lower potential energy than individual constituent parts.
Individual Nucleons
Bound Nucleons
E=mc^2

7. Energy –Mass Equivalence
E = mc2
E = energy (J)
m= mass (kg)
c = speed of light (3.0 x 108 m/s)
Energy and mass are related by a constant
If a system loses energy, it loses mass. If it loses mass, it loses energy.

8. Energy –Mass Equivalence
If a system loses energy, it loses mass. If it loses mass, it loses energy.
Energy is released
E = mc^2
Mass is lost!

9. 1 u = 931 MeV New units 1 atomic mass unit (u) = 1.661×10−27 kg
1 electron volt (eV) = 1.602×10−19 J
How much energy does 1 u have in eV?
E = mc^2
E = 1.66x10^-27 x 3x10^8 = x10^-10 J
E = 1.494*10^-10 / (1.602*10^-19) = 933 MeV (error due to rounding)
1 u = 931 MeV

10. Example problem Strategy: Find the mass defect
Particle
Mass
Neutron u
Proton u
Carbon -12 nucleus u
What is the binding energy of a carbon-12 nucleus?
Strategy:
Find the mass defect
Convert mass defect into energy

11. Example problem Strategy: Find the mass defect
Particle
Mass
Neutron u
Proton u
Carbon -12 nucleus u
What is the binding energy per nucleon of a carbon-12 nucleus?
Strategy:
Find the mass defect
Convert mass defect into energy
Divide the energy by the number of nucleons
The larger the energy per nucleon, the more tightly bound the nucleus is.