27.1 Introduction to Nuclear Physics
Introduction to Nuclear Physics
| Alpha particle |  | 4.00151u | +2e |  |
| Neutron |  | 1.00866u | 0 | |
| Proton |  | 1.00728u | +e | |
| Beta Particle |  | 0.00015u | -e | |
| Positron |  | 0.00015u | +e | |
| Gamma Ray |  | 0 | 0 |
• 1u = 1.66×10-27kg
The Nucleus and Nuclear Stability
| THE NUCLEUS AND NUCLEAR STABILITY | ||
|---|---|---|
| Atomic Number (Z) | # protons |  |
| Mass Number | # protons + neutrons | |
| Neutrons (N) | # neutrons | |
| Isotope | Same Z, different N | |
| • Elements with Z > 83 are radioactive. • Lighter elements are stable with N/Z = 1. • Heavier elements are stable with N/Z ≤ 1.6. |  | |
Nuclear Binding Energy
• The energy required to separate a nucleus into its constituent nucleons.
• A nucleus always weighs less than its constituent nucleons.
• Mass Defect – The difference in mass between the nucleus and the constituent nucleons.
• E = Δmc2 Δm = mass defect c = 3.0×108 m/s
• 56Fe has the highest nuclear binding energy per nucleon.