Particles and Radiation Goodnotes Recap Flashcards
Atom Composition?
An atom is made up of protons, neutrons and electrons
Nucleons?
The collective name for neutrons and protons which are located at the centre of the atom inside the nucleus
Atom properties?
Most of the atom is empty space. Electrons orbit the core at relatively large distance from the nucleus. Atoms have different charges and masses
Atom Charges?
A proton has a charge of +1.6x10-19 C. A neutron has a charge of 0 C. An electron has a charge of -1.6x10-19 C
Atom Masses?
The mass of a proton is 1.67 x 10-27 kg. The mass of a neutron is 1.67x10-27 kg. The mass of an electron is 9.11 x 10-31 kg.
Atom Relative Charge?
The relative charge of a proton is +1. The relative charge of a neutron is 0. The relative charge of an electron is -1
Atom Relative Mass?
A protons relative mass is 1. A neutrons relative mass is 1. An electrons relative mass is 0.0005.
Proton Number?
The proton number represents the amount of protons in the nucleus and is also called atomic number and has the symbol Z
Proton Number Property?
A proton number defines an element as no two elements can have the same proton number and this value defines the chemical properties of an atom
Number of Electrons Properties?
An element’s reaction and chemical behavior depends on the number of electrons. When the number of electrons is the same as the number of protons a neutral atom is created
Nucleon Number?
Also called the mass number and is the quantity that reveals the total amount of protons and neutrons in the nucleus and is identified by having the symbol A
Nucleon Number Property?
Since each proton and neutron have a relative mass of 1 and electrons have very little mass it means the nucleon number gives a good indication of the atoms mass
Nuclide Notation?
Summaries all the information about an elements atomic structure
Element Symbol?
The symbol to categories and element is with the letter X
Specific Charge?
The specific charge is the atoms ratio of its charge in relation to its mass. The units of specific charge is coulombs per kilogram ( C Kg-1)
Specific Charge Equation?
Specific Charge = Charge / Mass
Specific Charge = Q / m
Fundamental Particle?
A fundamental particle is a particle which cannot be split up into smaller particles
Specific Charge Equation Properties?
The specific charge of an electron is usually ratioed to the nucleus of an atom or ion. The charge of a fundamental particle like an electron can be worked out using this equation.
Isotopes?
An isotope is an atom with the same number of protons but a different number of neutrons
Number of Neutrons Properties?
Changing the number of neutrons doesn’t affect chemical properties but instead the stability of the nucleus. The more neutrons compared to protons the more unstable the nucleus is. Unstable nuclei may be radioactive and have to decay to be more stable
Hydrogen Isotopes?
Protium which has 1 proton and 0 neutrons. Deuterium which has 1 proton and 1 neutron. Tritium which has 1 proton and 2 neutrons.
Isotopic Data?
The relative amounts of different isotopes of an element present in a substance
Isotopic Data Use?
Scientists can calculate the age from dead matter by using isotopic data to find percentage of radioactive carbon-14 that is left in the object
EM Force in Nucleus?
The electromagnetic force causes positively charged protons in the nucleus to repel each other
Gravitational Force in Nucleus?
The gravitational force causes all nucleons in the nucleus to attract each other due to their mass
EM Force compared to Gravitational Force in Nucleus?
The repulsion of EM force is much larger than the attraction caused by the gravitational force
Strong Force stability?
The force that holds the nucleus together by balancing the repulsion from EM force and attraction from gravitational force so the nucleons in the nucleus don’t fly apart
Strong Force?
An attractive force stronger than EM force that has a very short range and has its strength fall beyond the distance of a few fentometres which is the typical separation distance in a nucleus between nucleons
Fentometre Conversion?
1 fentometre (fm) = 1 x 10 -15 metres (m)
Strong Force property?
At very small separation distances the strong force is repulsive and this happens to avoid the nucleons from imploding. Strong force works equally between all nucleons
Strong Force Separation Distances?
String force is repulsive for separations of nucleons less than 0.5 fm. Between 0.5 fm and 3 fm it is an attractive force with a maximum attraction at 3 fm. After 5 fm the strong force magnitude is very low and close to 0
EM force compared to strong force?
Electromagnetic force extends over a much larger distance than strong force
Nuclear Decay?
When unstable nuclei will emit particles to become more stable
Alpha Decay?
Has the symbol α and only happens in very large atoms as the strong force isn’t able to keep the nucleus stable due to how large they are. To become more stable these elements emit an alpha particle
Alpha Particle Notation?
An alpha particle has the nuclide notation of 4,2. The alpha particles nucleon number is 4 and its proton number is 2
Range of alpha decay?
Alpha particles have a very short range in air of only a few centimetres. The range of an alpha particle is tracked using a cloud chamber, Geiger counter or spark chamber. This equipment measures the amount of ionizing radiation. The reading rate significantly decreases after a few centimetres from a source of alpha decay.
Beta Minus Decay?
Has the symbol β- and this is the emission of an electron from the nucleus with an anti-neutrino and occurs due to an atom being neutron rich.
Neutron Rich?
This is where the nucleus has too many neutrons compared to protons in the nucleus
Process of beta minus decay?
When a neutron ejects a beta particle one of the neutrons changes into a proton. Beta minus decay increases the proton number but keeps the nucleon number the same. The anti-neutrino released carries some of the left of energy and momentum to conserve the interaction
Neutrino Discovery?
The neutrino was observed and proved in 1955 which provided evidence for Pauli’s claim
Beta Particles compared to alpha particles?
Beta particles have a much greater range than alpha particles and can travel a few metres in air
Neutrino History?
Scientists originally thought just an electron was emitted in beta decay. Pauli suggested a neutral particle with nearly zero mass was emitted. This was accepted and named the neutrino and the evidence for Pauli’s claim happened in 1955
Electromagnetic Spectrum?
A continuous spectrum with all frequencies of electromagnetic radiation
Frequency and Energy relationship?
The higher the frequency of electromagnetic radiation the more energy it has
Order of EM Spectrum in terms of wavelength?
Radio Waves -> Microwaves -> Infared -> Visible Light -> Ultraviolet -> X-Ray -> Gamma Ray
Max Planck theory?
Investigated black body radiation and suggested EM waves can only be released in packets which are also referred to as quanta
Photon Equations?
E = hf
Energy = Planck’s Constant x Frequency
f = hc / λ
Frequency = (Planck’s Constant x Speed of light) / wavelength
hf = hc / λ
Planck’s Constant x Frequency = (Planck’s Constant x Wave Speed) / Wavelength
Frequency?
Number of waves passing a point per second
Wavelength?
The distance between 2 adjacent peaks or troughs of a wave
Anti-Particle?
Composed of anti-matter instead of matter and has the same mass and rest energy but opposite charge in relation to is corresponding particle made of matter
Proton and anti proton data?
Have symbol “p” and “ˉp”. Have a relative charge of +1 and -1. Both have a mass of 1.67x10-27 kg. Both have a rest energy of 938 MeV
Neutron and anti neutron data?
Have the symbol “n” and “ˉn”. Both have a relative charge of 0. Both have a mass of 1.67x10-27 kg. Both have a rest energy of 939 MeV
Electron and positron data?
Have the symbol of “e -“ and “e +”. Have the relative charge of +1 and -1. Both have a rest mass of 9.11x10-31 kg. Both have a rest energy of 0.51 MeV.
Neutrino and Anti-neutrino data?
Have the symbol “ν “ and “ν -“. Both have a relative charge of 0. Both have a relative mass of 0 kg. Both have a rest energy of 0 MeV.
Einstein Theory?
Energy can be turned into mass and mass can be turned into energy
Pair Production?
When energy is converted into mass and the result is equal amounts of matter and anti-matter.
Condition of Pair Production?
It can only occur if there is enough energy to produce the particles’ masses. Conservation of anti-particles and particles mass and energy must happen
Additional particles in pair production?
If additional particles are produced from the collision there will be corresponding anti-particles made for the new particles
Electron-Positron pair compared to proton-anti-proton pair?
An electron-positron pair requires a higher photon energy in order to allow the pair production to happen between the particle and anti-particle
Electron-Positron Pair conditions?
Typically are made when a photon passes near a nucleus. If they are produced in a detector the pair curves in opposite directions because of the applied magnetic field and the pair having opposite charges
Rest Energy?
Has the symbol E 0. It is the amount of energy that is required to transform mass into energy
Total Rest Energy?
The minimum amount of energy to allow pair production to happen
2 E 0?
The minimum amount of energy to produce the mass of particles and antiparticles and allow conservation of energy in pair production
Energy in Pair Production equation?
E min = 2 E 0
Minimum Energy in MeV = 2 x rest energy of produced particle in MeV
Electron-Positron Pair factor?
Electron-Positron pairs are the most common particle anti-particle pair in pair production due to the relatively low mass involved
Annihilation?
When a particle meets its anti-particle and all the mass gets converted into energy to form 2 gamma ray photons
Anti-particles formation?
Anti-particles don’t appear as ordinary matter as they only exist for a fraction of a second before they are annihilated
Energy in annihilation?
The rest energy in annihilation has the symbol E 0 and the photons minimum energy in this process can be calculated. 2 photons are needed so rest energy for conservation has to be at least 2 E 0 = 2 E min
Annihilation equation?
E min = E 0
minimum energy of a photon = rest energy of annihilated particle in MeV
PET scanners function?
A positron emitting isotope detected by gamma rays from annihilation. The gamma rays travel in opposite directions and the radiation is detected by a scintillator which identifies the paths they’ve travelled
Hadrons?
The particles that can feel strong force and are made up of quarks but are not fundamental particles. The two types of hadron are the baryon and meson
Baryon decay?
All baryons except a free proton can be unstable. Apart from a free proton all baryons will decay into other particles until they’re in the form of a free proton
Sigmas?
Has the symbol Σ and are baryons not made of ordinary matter
Common Baryon examples?
Protons and Neutrons are both baryons
Anti-Baryons?
The corresponding anti-particles to the baryon particles. They don’t exist in ordinary matter due to their annihilation from the corresponding particle
Quantum Number?
A number which must be conserved in all interactions
Baryon Number Trends?
All baryons will have a baron number of +1. Anti-Baryons will have a baryon number of -1. All non-baryons will have a baryon number of 0. Baryon number is constant in all interactions and is used to show if interactions can happen with its conservation
Beta Decay Cause?
Beta decay is caused by a weak interaction from a down quark turns into an up quark. This causes a neutron to decay into a proton, electron and electron anti-neutrino
Mesons?
A type of hadron that can interact with baryons through strong force. They are unstable and non-baryons which give them a baryon number of 0 as they are made up of a singular quark and anti-quark
Computer simulations?
What is used to predict what can happen in particle collisions by predicting paths and products of interactions
Pions?
The lightest meson and has the symbol π. The types of pion are π+, π0, π-. π0 is its own anti-particle and π- and π+ are anti-particles of each other. They are the exchange particle of strong force
Kaons?
Heavier and more unstable than pions. Have a very short lifespan and decay into pions. Only mesons with strangeness. K0 is its own anti-particle. K + is the anti-particle of K -
Cosmic Rays?
High energy particles constantly hitting the Earth and interact with molecules in the atmosphere producing showers of high energy particles involving mesons like kaons and pions
Cosmic Ray Showers?
Can be observed in cloud chambers. Where high energy particles interact with molecules in the atmosphere. 2 Geiger counters placed above each other separated by an absorbing lead detecting radiation simultaneously are the counters detecting a particle from a cosmic ray shower instead of background radiation.
Leptons?
Fundamental particles that aren’t affected by strong force and are not made up of quarks and only react through weak interactions
Charged Lepton?
If a lepton has a charge then it is able to react with the electromagnetic force as well as the gravitational force
Stable lepton?
The most stable lepton is the electron which has the symbol e-
Muon?
Has the symbol μ and are heavy electrons that are unstable and will eventually decay into electrons
Neutrinos?
A particle with almost zero mass and no charge and have flavours based on types of muon. They only take part in weak interactions.
Electron and Positron data?
Has the symbol e- and e+. Has a relative charge of +1 and +1. Has a lepton electron flavour of +1 and -1. Has a lepton muon flavour of 0 and 0
Electron Neutrino and Electron Anti-Neutrino data?
Has the symbol ν e and ν e-. Have a relative charge of 0 and 0. Has a lepton electron flavour of +1 and +1. Has a lepton muon flavour of 0 and 0.
Muon and Anti-Muon data?
Has the symbol μ− and μ+. Have a relative charge of -1 and +1. Has a lepton electron flavour of 0 and 0. Has a lepton muon flavour of +1 and +1.
Muon Neutrino and Muon anti-neutrino data?
Has the symbol ν μ and ν μ-. Has a relative charge of 0 and 0. Has a lepton electron flavour of 0 and 0. Has a lepton muon flavour of +1 and +1.
Lepton properties?
Created by strong interactions. A property conserved only in strong interactions and not weak interactions. Strange particles can only be created in pairs. All leptons have a strangeness value of 0
Strangeness Quantum Number Values?
-1,0,1
Conservation of properties?
Energy, Momentum, baryon number, lepton number, charge and strangeness but only in strong interactions not weak interactions are all conserved in interaction equations
Weak interaction property?
A property of weak interactions is it is the only way a type of quark can change with this interaction
Strangeness Conservation Properties?
Strangeness is conserved in some weak interactions like beta decay. Strong interactions has strangeness conserve as the quarks involved don’t change with this interaction
Types of Quarks?
There are 3 types of quarks that are up, down, strange. There are also corresponding anti-quarks with opposite quantum values
Up and Anti-Up quark data?
They have the symbols u and u-. They have a charge of 2/3 and -2/3. A baryon number of 1/3 and -1/3. They both have a strangeness of 0
Down and Anti-Down quark data?
They have the symbols d and d-. They have a charge of -1/3 and 1/3. They have a baryon number of 1/3 and -1/3. They both have a strangeness of 0.
Strange and Anti-Strange quark data?
Have the symbols s and s’. They have a charge of -1/3 and 1/3. They have a baryon number of 1/3 and -1/3. They have a strangeness of -1 and +1
Anti-quarks?
This is what forms the hadrons called antiparticles and have the opposite properties to quarks
Quark Composition factor?
The quark composition decides what the properties of the particle they form are
Quark Factors?
All baryons and anti-baryons are made up of 3 quarks. Leptons are not made up of quarks. Muons are made up of a quark, anti quark pair.
Quark History?
Murray Gell-Mann in 1969 predicted the existence of quarks and won a nobel prize for his discovery
Pions compared to kaons?
Pions are made from combinations of up quarks, anti-up quarks, down and anti-down quarks. Whereas, kaons are also made up of these but with the addition of a strangeness from a strange quark
Structure of kaons?
k+: us-
k-: su-
k0: ds-
Structure of pions?
π0: uu-, ss-, dd-
π-: du-
π+: ud-
Quark confinement?
The energy used to try and remove a quark but make an anti-quark quark pair of that quark in pair production as an isolated quark cannot exist
Quark Character?
The process of changing one quark into another
Weak interaction and Quarks?
A weak interaction is the only interaction that can change the quark strucuture of interacting particles. For example, In beta minus decay the neutron changing into a proton is the result of a down quark changing to an up quark
Beta Plus decay?
A proton turns into a neutron, positron, and an electron neutrino through a weak interaction. This leads to the nucleon number staying the same and the atomic number increasing by +1.
B+ meaning?
This symbol represents a positron being released otherwise the +1 in the equation
Hypothesis of particles?
Paul Dirac predicted the existence of anti-matter. The neutrino was hyporhesised due to observations in beta decay. Hypotheses are the foundation of new ideologies being accepted by the scientific community
Particle Exchange Importance?
All forces are caused by particle exchange. Instantaneous action cannot happen at a distance. This means when 2 particles interact they exert a force on each other. Exchange particles then let each particle know where the other one is so they can interact
Exchange Particles discovery?
Exchange particles were first discovered in 1983
Principle of Repulsion?
The exchange particle carries momentum between particles causing a force between them which is repulsion
Principle of Attraction?
An exchange particle identifies the opposite momentum between particles and alerts the particles the force they are going to impose on each other
Exchange Particles?
Virtual particles which allow forces to act between 2 particles only
Virtual Particles?
Particles that only exist for a short amount of time but long enough to transfer energy and momentum between particles and after this are gone
Forces Causes?
All forces are caused by the 4 fundamental forces of strong force, weak force, gravitational force, electromagnetic force
Gauge Bosons?
The particles that belong to fundamental forces and allow forces to act in particle interactions. They are also refered to as exchange particles
Exchange Particle interaction types?
Strong force has the gauge boson of the pion, π+, π-, π0, and affects only hadrons, EM force has the gauge boson of virtual photons and affects all charged particles, Weak force has the gauge boson of W+ and W- and affects all particle types
Exchange Particle Ranges?
Exchange particles are size dependant on the range of the force they provide. Heavier exchange particles provide a shorter range force because of energy they require to travel to move their mass
Particle Interaction Diagrams?
Exchange particles path is identified by squiggly lines and other particles are shown with straight lines of their paths. These diagram explain compilcated ideas in simple drawing rather than using calculations. These were created by Richard Feyman
Feyman Diagram Property?
Particle Interaction diagrams are only used for interactions involving electromagnetic force and weak force. Incoming particles move to top of diagram. Baryons stay on the left and leptons on the right if not all baryon or lepton. W+ bosons carry charge in the right direction and W- in the left direction
Equations for Feyman Diagrams?
Beta Minus Decay: n -> p + e- + ν-
Beta Plus Decay: p -> n + e+ + v
Electron Capture: p + e- -> n + v
Electron-Proton Collision: p + e- -> n + v
Electromagnetic Repulsion: e+ + e+ -> e+ + e+ and e- +e- -> e- + e-
Proton Rich?
An electron is captured and turned into a neutron by interacting with a proton through a w+ boson.
Boson Types in Feyman Diagrams?
Beta Minus Decay: w- boson
Beta Plus Decay: w+ boson
Electron Capture: w+ boson
Electron-Proton Collision: w- boson
Electromagnetic Repulsion: Virtual Photon
Factors of electron capture?
W+ boson comes from the proton, an electron anti-neutrino is released to conserved electron lepton number
Electron-Proton Collision and Electron Capture Difference?
An electron-proton collision has a w- boson travelling in left direction instead of electron capture which has a w+ boson travelling to the right
Electron-Proton Collision Factor?
W- boson comes from the electron as thats the particle acting to cause the interaction.
Electromagnetic Repulsion?
When 2 particles of equal charge get close they repel and this is due to the gauge boson of a virtual photon
