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Interactive Syllabus Extract for Module 1

Section 3.1.1 - Particles and Radiation

Particle section notes link

		Useful background	You should be able to:
Constituents of the atom	proton, neutron, electron - their charge and mass in SI units and relative units. Specific charge of nuclei and of ions. (Atomic mass unit is not required). Proton number Z, nucleon number A, nuclide notation, isotopes	Evidence for existence of the nucleus, qualitative study of Rutherford scattering was covered at GCSE - revise it!	- draw from memory a fully labelled diagram of the atom - draw from memory a table with relative masses, positions and charges of electron, proton and neutron - appreciate the size of the atom and its nucleus
Stable and unstable nuclei	The strong nuclear force; its role in keeping the nucleus stable; short-range attraction to about 3 fm, very-short range repulsion below about 0.5 fm; Equations for alpha decay and - decay including the neutrino		Strong force acts between baryons
Particles, antiparticles and photons	Candidates should know that every particle has a corresponding antiparticle. They should know that the positron, the antiproton, the antineutron and the antineutrino are the antiparticles of the electron, the proton, the neutron and the neutrino respectively. Comparison of particle and antiparticle masses, charge and rest energy in MeV. Photon model of electromagnetic radiation, the Planck constant, Knowledge of annihilation and pair production processes and the respective energies involved. The use of E = mc² is not required in calculations	interactive spreadsheet on the Einstein Equation	- recall the electromagnetic spectrum in order of energies. - recall and use the equation defining the terms and using the correct units Interactive worksheet- recall the names and symbols of particles and their antiparticles and which group they belong to - use the conservation laws to say whether a reaction is possible or not
Particle Interactions	Concept of exchange particles to explain forces between elementary particles. The electromagnetic force; virtual photons as the exchange particle. The weak interaction limited to β^-, β⁺ decay, electron capture and electron-proton collisions; W⁺ and W^-as the exchange particles. Simple Feynman diagrams to represent the above reactions or interactions in terms of particles going in and out and exchange particles.		- sketch the given Feynman diagrams for beta decay, positron decay, electron capture, particle collisions - know that the changes from a proton to a neutron and vice versa occur via the weak interaction (using a boson as an exchange particle) - use the concept of exchange particles to explain forces between elementary particles - explain why particles 'appear in pairs' - understand that a particle and its antiparticle annihilate to release energy in the form of a gamma ray
Classification of particles	- Hadrons: baryons (proton, neutron), antibaryons (antiproton and antineutron) and mesons (pion, kaon) To know that hadrons are subject to the strong nuclear force. Candidates should know that the proton is the only stable baryon into which other baryons eventually decay; in particular the decay of the neutron should be known Leptons: electron, muon, neutrino (electron and muon types) - leptons are subject to the weak interaction Candidates will be expected to know, baryon numbers for individual particles and antiparticles - lepton numbers are given in the data pullout.		- recall that baryons and mesons are called hadrons and name two of each - recall that baryons have 3 quarks - recall that antibaryons have 3 antiquarks - understand that hadrons are subject to the strong nuclear force whereas beta decay reactions are via the weak nuclear force - know that mesons are made up of a quark and an antiquark and that the only strange particle you have to deal with (the one with a strangness quark) is the kaon - know that the proton is the final stage of baryon decay - appreciate the neutron into proton Feynman diagrams as representing that decay process (β^- decay). - recall the names of three leptons and understand that they are fundamental particles (do not break down into anything simpler)
Quarks and antiquarks	Up (u), down (d) and strange (s) quarks only. Properties of quarks: charge, baryon number and strangeness Combinations of quarks and antiquarks are required for baryons (proton and neutron only) and for mesons (pion and kaon only) Change of quark character in β^- decay and β⁺ decay Application of the conservation laws for charge, baryon number, lepton number and strangeness to particle interactions. The necessary data will be provided in questions for particles outside those specified.		- work out the quark composition of a given hadron, using the table of quark properties on the data sheet - simplify the β^- decay processes into quark interchange - be able to work out what happens in a the following situations by using the conservation laws and the fact that in all of these the neutron changes into a proton or vice versa: β^- decay β⁺ decay electron capture neutrino – neutron collisions antineutrino – proton collisions electron – proton collisions Try atom builder... great fun!