The Atomic Nucleus: Binding Energy, Mass Defect, Nuclear Forces and Reactions
Why a nucleus weighs less than its parts, and where the energy of stars and reactors comes from
Big Idea: An assembled nucleus is lighter than the free protons and neutrons that make it up. The tiny missing mass, the mass defect, has been converted into the binding energy that glues the nucleus together, following Einstein's E = mc2. Releasing even a fraction of this energy powers the Sun, nuclear reactors and the atomic clocks of modern physics.
By the end you will be able to:
- describe the composition of a nucleus using Z, N and A, and read nuclide notation;
- explain what isotopes are;
- state the properties of the nuclear (strong) force;
- calculate the mass defect and the binding energy of a nucleus;
- use the conversion 1 u = 931.5 MeV/c2;
- read the binding-energy-per-nucleon curve and apply conservation laws to nuclear reactions.