Nuclear and Particle Physics Flashcards
What range is the strong nuclear force repulsive?
When the separation distance is less than 0.5fm
What range is the strong nuclear force attractive?
When the separation distance is between 0.5-3fm
Which particles are affected by the strong nuclear force?
Hadrons
What is the value of atomic mass unit
1.66x10^-27 kg
What causes Beta decay?
The weak nuclear force
What are 3 examples of a hadron?
Proton, neutron, mesons
What are 3 examples of leptons?
Electrons, neutrinos, muons
How does the Alpha Particle scattering show the structure of an atom?
Most of the alpha particles went straight through showing that the atom is mostly empty space.
A few were deflected which shows the atom has mass concentrated in the centre and has a positive charge.
What is induced nuclear fission
A slow moving neutron splits a nucleus into two smaller nuclei and fast moving neutrons.
Explain the purpose of the moderator and control rods
- Fission reactions produce fast neutrons
- the moderator/ water slows down the neutrons
- slow moving neutrons have a higher chance of causing fission
- the control rods absorb neutrons so exactly one slow neutron survives per fission reaction.
Define the decay constant
The probability of decay of a nucleus per unit time
Explain how carbon dating works
- Living plants/ animals absorb carbon 14
- when dead they do not absorb anymore carbon-14
- Activity of c-14 measured in alive and dead sample
- x=xe^-t used to estimate age
Define activity
The number of nuclei decaying per second.
Describe the differences and similarities between fusion and fission
Similarities
-both release energy
-conserve charge
Differences
-Fission releases more energy than fusion
-Fusion needs hot temperatures
-rate of fission can be controlled by absorbing neutrons
What is the radius of a proton
1.2fm
10^-15
