Properties Of Particles Flashcards
(18 cards)
Which of the two main groups of particles contain only fundamental particles
Leptons
Which particles are classified as leptons
Electrons
Muons
Electron neutrinos
Muon neutrinos
What quantities are always conserved in particle interactions
Momentum
Energy
Charge
Baryon number
Lepton numbers
What quantity is conserved in strong but not weak interactions?
Strangeness
What value does strangeness take
-3 to +3 for hadrons
0 for leptons
What are antihadrons made up of
Antiquarks
Give the quark composition of a proton
uud
Whats the quark composition of a sigma particle
Any three quarks but must include a strange quark
Whats the photoelectric effect
Emission of electrons from the surface of a metal when EM radiation above a certain frequency is incident on it
Define the threshold frequency of a material
Minimum frequency of photons needed for photoelectric emission of electrons from the surface of the metal
What is excitation of an atom
When an electron moves up an energy level
When an electron moves down energy levels what does it emit
Energy in the form of a photon
What do each of the coloured lines in a line spectrum represent
A particular wavelength and therefore frequency of light emitted by the source
When does ionisation occur
When an electron gains enough energy to leave the atom
Define an electron volt
Energy gained by an electron accelerated through a pd of 1V
Identify the phenomena that can only be explained by the wave model of light
Diffraction and interference
What did de broglie propose about th nature of particles
All matter particles have wave properties
What must the total charge, baryon number and strangeness of a hadron equal
The sum of these values for three quarks of which its composed (always integers)
