Relativity

A nuclide with the same number of protons (Z) but a different number of neutrons (N)

A nuclide with the same N but different Z

An isobar is a nuclide with the same atomic mass (A = Z+N) but with differing Z and N.

The unit of area in subatomic physics is the barn . where 1 barn = $100 (fm)^2$ . It is approximately the cross section of $U_{238}$

The standard unit of energy in sub-atomic physics (SAP) is the MeV where:
1 MeV = $10^6 eV =1.6\times10^{-13}J $
This is the typical scale of energy needed to split a nuclide (2.2 MeV splits deutron).

time = [s]
mass = [1u] = $\frac{931.494 MeV}{c^2}$
which is 1/12 of the mass of a C12 nucleus.

STATIC: do not change
- electric charge, radius, mass, binding energy, angular momentum, parity, magnetic dipole.
DYNAMIC: do change
- decay and reaction probabilities

Rutherford scattering measures the strong nuclear force (SNF) to determine the distribution of matter in the nucleus. Alpha particles were chosen to be the probe of the gold nucleus.

- Some alpha particles were scattered at large angles, since they are positively charged, this means that the positive charge in the nucleus is highly concentrated, unlike the negative charge of the atom as a whole.