Download Nuclear and Particle Physics

Nuclear and Particle
Physics
Understand the structure of matter,
from the atomic nucleus to
fundamental forces.
Understand radioactivity, fusion and
fission.
Nuclear and Particle Physics
What does an atom look like and how do we know?
Nuclear and Particle Physics
Nuclear and Particle Physics
Nuclear and Particle Physics
Nuclear and Particle Physics
What was expected v what actually happened?
How big is a nucleus, e.g. gold?
The size of the nucleus
What is Coulomb’s law?
The charge on an alpha particle is +2e
The charge on a nucleus is +Ze
Nuclear and Particle Physics
d = 3.0 x 10-14 m
This would be a maximum possible radius for a gold atom
In general, radius of an atom is 10-10 m
and the nucleus is 10-15 m
What prefix would be suitable for nuclear dimensions?
Nuclear and Particle Physics
Diameter = 22cm
Nucleons
Nucleons refers to either a proton or a neutron
Protons have a charge +e
Atomic Mass Units
Atomic mass units, u, 1u is one twelfth the
mass of a neutral carbon-12 atom
1u = 1.661 x 10-27 kg
Compare this to the mass of a proton or
neutron in your formula sheet
Nucleon Size and Density
A gold nucleus is much bigger than a hydrogen nuclear
The size of a nucleus depends on the number of nucleons
1
3
R= r0 A
Radius of nuclei
Nucleon Number
1fm
Estimate the density of a nucleus
Nuclear and Particle Physics
Plot a graph of the radius of the nucleiagainst
atomic number (up to 150)
Nuclear and Particle Physics
The Strong Force
How do all the positive protons in a nuclear stay together.
They should repel ……..
Calculate the force between two protons in a helium nucleus.
The Strong Force
The gravitational force is not enough to
hold the nucleus together
The strong force acts between all nucleons
Nuclear and Particle Physics
The Fundamental Forces
Electromagnetic Gravitational
Strong
Weak
Most
elementary
particle
<10-17m
Acts On
Electric Charge
Mass
Nuclear
Particles
Range
Infinite
Infinite
10-15m
Weak
Strongest
Strength
Nuclear and Particle Physics