Particles and Waves Flashcards
Right and left hand rules
Left hand rule is for electrons
right hand rule is for positive particles
Thumb - force
Index finger - field
Middle finger - flow of particles
How do particle accelerators work
Electrons are ejected from the cathode an are accelerated due to the potential difference. After they pass the anode they continue at constant speeds and then repeat the process.
Name all 6 types of quarks
Top and bottom quarks
strange and charm quarks
up and down quarks
Combinations of quarks
A combination of quarks is known as a hadron.
A meson consists of two quarks.
A baryon consists of three quarks.
protons and neutrons are baryons.
Charges on quarks
up quark - 2/3
down quark - -1/3
anti up quark - -2/3
anti down quark - 1/3
Name all 6 types of leptons
Electron and electron neutrino
Tau and tau neutrino
Muon and muon neutrino
What are the fundamental forces
Gluon - strong nuclear force
W and Z bosons - weak nuclear force
Photons - electromagnetic force
Gravity
What is beta decay?
It is when a neutron decays into a proton and an electron.
The nucleus then recoils the electron away.
A ghost particle called the neutrino is there too.
What is a neutrino?
It is a ghost particle said to carry away the excess energy that the electron doesn’t during beta decay.
What is anti matter?
It is when an anti-particle has the same mass but opposite electric charge as their equivalent particles.
What is alpha decay?
It is the emission of 2 neutrons and 2 protons from the nucleus in the form of a helium nucleus
What is nuclear fusion?
When two elements combine to make a new element and release huge amounts of energy. They must be at very high speeds and temperature to fuse together.
What is nuclear fission?
When a neutron enters a nucleus and splits into two smaller nuclei releasing massive amounts of energy and more neutrons which would then cause a chain reaction as they would enter more nuclei.
What is irradiance
Irradiance is the power incident per unit area
I = P/A
I1 d1 squared = I2 d2 squared
What is the photoelectric effect?
When intense light falls on to a negatively charged metal. If the energy transferred to the electrons is sufficient enough, they will leave the metal (photoemission).
Equations of photoemission?
E = hf Eo = hfo Ek = hf - hfo
What are coherent sources
It is when two sources of waves interfere and have the same frequency, wavelength, velocity and have a constant phase relationship.
What is constructive interference
Its when two coherent sources interfere at a point where the path difference of the waves is a whole number. crest to crest or trough to trough.
Path difference = m lamda where m is (1,2,3,4 etc.)
What is destructive interference?
Its when two coherent sources interfere at a point where the path difference of the waves is half a whole number. crest to trough or trough to crest.
Path difference = (m+1/2) lamda where m is (1,2,3,4 etc.)
What is a free atom?
One that does not experience forces due to surrounding atoms
Name 3 states / orbits that an electron can move between
Ground state - lowest, most stable
exited states - the levels in between
Ionisation level - zero potential energy and can escape the atom.
Information about the energy levels
Each state has a specific energy associated with it and for an electron to move between the levels, it needs to absorb or emit energy in the form of photons of light. it needs the exact amount of energy to move levels.
What is the critical angle?
The critical angle is the incident angle at which the light refracts at a 90 degree angle from the normal
What is total internal refraction
When the angle in the medium is larger than the critical angle and no light is refracted.
What happens when light enters a medium
The light separates into its component colours and produces a spectrum. This happens because each colour is refracted by different amounts. The refractive index for each colour is different.
