Particles and Radiation Flashcards
Charge of a Proton
+1.6 x 10⁻¹⁹
Charge of a Neutron
0
Charge of an Electron
-1.6 x 10⁻¹⁹
Mass of a Proton
1.67 x 10⁻²⁷
Mass of a Neutron
1.67 x 10⁻²⁷
Mass of an Electron
9.11 x 10⁻³¹
Photon Energy
E = hf Energy = plancks constant x frequency of light
Plancks Constant
6.63 x 10⁻³⁹ Js
Minimum energy need for pair production
Eₘᵢₙ = 2E₀ E₀ = rest energy of particle type produced
What is a baryon
Protons and neutrons are both baryons. All baryons (except a free proton) can be unstable. All baryons eventually decay to a proton. The baryon number must remain the same in interactions.
What is a meson
Mesons interact with baryons via strong force. All mesons are unstable. There are two types, Pions and Kaons
What is a lepton
Leptons are fundamental particles and they don’t feel strong nuclear force. They interact via weak interaction (and electromagnetic force if charged). Electrons are stable leptons, muons are unstable leptons and decay into electrons. They both come with their own neutrino which only takes part in weak interactions
Define a nucleon
A proton or a neutron in the nucleus
Define an isotope
Isotopes are atoms with the same number of protons and different numbers of neutrons
Define the term specific charge
The ratio of the charge of a particle to its mass
How do you calculate specific charge
charge divided by mass
Name the force that holds nuclei together
Strong nuclear force
What is the range of strong nuclear force
0.5 to 3 femtometres
List the 7 main parts of the em spectrum
Radio waves, Microwaves, Infrared, visible light, UV, X-rays, gamma rays
Define a photon
A discrete packet of energy
Define an electron volt
One electron volt is the kinetic energy gained by an electron when accelerated by a PD of 1 volt
Define pair production
A process in which a photon of EM radiation ceases to exist, creating a particle and anti particle
How do you convert from MeV to J
x by 10⁶ x by 1.6 x 10 ⁻¹⁹
What is the photoelectric effect?
Represented by the equation hf = ∅ + Ek. When the discrete packet of energy is greater than the work function ,∅, then the excess energy enables electrons to be emitted from the surface. This excess energy is proportional to the kinetic energy
Four fundamental interactions
Gravity, EM, weak nuclear, strong nuclear
What is the the exchange particle for an em force
The virtual photon
What is exchanged in a weak nuclear force?
W boson
What are strange particles?
Particles that are produced through the strong interaction but decay through the weak interaction
What is conserved in an electromagnetic force
Momentum
What is a PET scanner
Stands for positron emission tomography. It is used to detect gamma rays emitted when annihilation happens.
What is annihialtion
When a particle and anti-particle collide to produce two photons that move in opposite directions to conserve momentum
What are baryons
Consist of 3 quarks
What is the most stable baryon
protons
What are mesons?
Consist of a quark and anti-quark and are a pion and kaon
What is the exchange particle of the strong nuclear force?
gluon
What do pions decay into
Kaons
What type of interactions are leptons involved in
Weak interaction
What are the three leptons
Electrons, muons and neutrinos
What is the equation for rest energy
Total energy before - kinetic energy of the products
What is the charge on an up quark
+2/3
What is the strong force
Binds quarks together in clusters. It also holds together the atomic nucleus and underlies interactions between all particles containing quarks
What is weak nuclear force
Governs the decay of unstable subatomic particles and initiates nuclear fusion reactions. Exchange particle is the W or the K boson. Strangeness is not conserved.
What is conserved during particle interactions?
Baryon Number
Lepton Number
Charge
Strangeness
