Section 1: Particles & Radiation Flashcards
What is the realtionship between specific charge and mass?
specific charge is inversly proprtional to mass
How do you find specific charge?
Charge/ mass
What is meant by spesific charge of a particle? untis?
the ratio of its charge to mass (C kg-1)
describle how the strong nuclear force varies with the spereation of neuclons.
- repulsive then attractive
-short range (0.5- 2.5) fm ish - cross to atractive around 0.7 fm
-prevents protons and neutrons from moving closer or further apart
What neucles is the same as a alpha particle?
helium neucleus
What is the neuclon number?
number of protons and neurons, mass number
What guage boson is used in strong interaction? and what particles are effected?
guage boson - pion (0+-)
particles - hadrons
What guage boson is used in electromagnetic interaction? and what particles are effected?
virtual photon
only charged particles
What guage boson is used in weak interaction? and what particles are effected?
w+ w- bosons
all types of particles are effected
What is the equation for beta minus decay? and what is the guage boson present?
n—> p + electron + anti-neutrino. W-
What is the equation for beta plus decay? and why is the guage bosson present?
P—> n + (e+) + neutrino W+
What is the equation for electron capture? and what is the guage bosson present?
P + e- —> n + netrino W+
What is the equation for electron proton collision? What is the guage bosson present (why)?
Same as electron capture
P + (e-) —> n + neutrino
W- bosson because:
-comes from the electron
- W- to conserve charge
What do kaons decay into?
Pions
How do you find the minimum energy for anhilation?
min energy of EACH photon = rest mass
How do you find the minimum energy for pair production?
min energy of photon = 2x rest mass of the particle made
How does a K- particle decay?
k- —> Pion 0 + (e-) + anti neutrino
Explain what is meant by electron capture?
- an orbital/shell electron
- interacts with a proton in the neuclus
- via the weak interaction
State what roles exchange particles can play in an interaction.
- transfer energy
-transfer momentum
-transfer force
(somtimes) transfers charge
What is an electrons lepton numbers and charge?
Le +1 lu 0 charge -1
What is an electron neutrino lepton numbers and charge?
Le +1 lu 0 charge 0
What is an muons’ lepton numbers and charge?
Le 0 lu +1 charge -1
What is a muon neutrino lepton numbers and charge?
Le 0 Lu+1 charge 0
What patricle is the only stable baryon?
proton
What are caracterisitcs of a strange particle that makes it diffrent to particles that are not strange?
- contains a strange quark
- longer half life than expected
-decays by the weak interaction
What is annhilation?
The process of a particle and its antiparticle colliding and being converted into energy. The energy is released in two photons to conserve momentum.
What are the products of pair production?
Two protons fired together - A proton anti proton pair.
A gamma photon -An electron positron pair
What interaction is present for the dacay of strange particles? Is strangeness conseverd?
Weak interaction
Not always conserved
In what sized atom does alpha decay usually happen?
In atoms with more than 82 protons
Antiparticle:
All particles have a corresponding antiparticle with the same mass but opposite charge and conservation numbers.
What do muons deacy into?
Electrons
Stopping Potential:
The minimum potential difference required to stop the highest kinetic energy electrons from leaving the metal plate in the photoelectric effect.
Threshold Frequency:
The minimum frequency of photons required for photoelectrons to be emitted from the surface of a metal plate through the photoelectric effect. It is equal to the metal’s work function divided by Planck’s constant.
Work Function:
The minimum energy required to remove an electron from a metal’s surface.
