1What is an isotope?
A nuclide with the same number of protons (Z) but a different number of neutrons (N)
2What is an isotone?
A nuclide with the same N but different Z
3What is an isobar?
An isobar is a nuclide with the same atomic mass (A = Z+N) but with differing Z and N.
4What is the unit of area in subatomic physics (SAP)? What is its physical significance?
The unit of area in subatomic physics is the barn . where 1 barn = $100 (fm)^2$ . It is approximately the cross section of $U_{238}$
5What is the unit of energy in SAP? What is its physical significance?
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).
6What are the typical units for time and mass in SAP? What is the physical significance of the mass unit chosen?
time = [s]
mass = [1u] = $\frac{931.494 MeV}{c^2}$
which is 1/12 of the mass of a C12 nucleus.
7STATIC: do not change
- electric charge, radius, mass, binding energy, angular momentum, parity, magnetic dipole.
DYNAMIC: do change
- decay and reaction probabilities
8What is the aim of Rutherford scattering? Which of the 4 fundemental forces is it probing? Which particles were used as probes?
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.
9Describe and explain the significance of large scattering angles in the Rutherford scattering experiment.
- 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.