What is it? It's basically just a table of all the subatomic particles that we know of. They're split into 3 different groups, the quarks, the leptons, and the gauge bosons. Important:Before I cause mass terror, I feel I must mention that you do actually get a FULL standard model in the IB Physics data booklet. It's amazing and it makes life so much easier when answering questions in this topic! QuarksIf you look at the diagram above, you can see the charges on the different quarks. A proton is made from 2 up quarks and 1 down quark. The 2 up quarks give a charge of 4/3 and the down quark has a charge of -1/3 which gives the proton a total charge of +1 (3/3). The neutron on the other hand has 2 down quarks and an up quark. The 2 down quarks give a charge of -2/3 and the up quark has a charge of +2/3, so the neutron has a total charge of 0. LeptonsThe leptons are another group of 6 sub atomic particles.
The gauge bosonsThese are the exchange particles for the 4 forces. The 4 forcesElectromagneticThe electromagnetic force deals with everything electricity, magnetism and light. It's exchange particle is the photon (I'll explain later). It has an infinite range, but only acts on matter that carries electrical charge. It's exchange particle is the photon (particle of light!). Strong ForceThe strong force holds particles together in the nucleus. It may be the strongest of the forces (hence the name), but it only has a range of 10^-15 metres. The exchange particles are called gluons (ugly names) Weak ForceThe weak force is the key force that acts in radioactive decay, it allows quarks to change into other quarks in very strange ways. If an up quark changes to a down quark in a proton, it becomes a neutron (think about it) which is one of the key stages in radioactivity. The weak force has 3 different exchange particles, the W+, W- and Z bosons. Gravitational forceThe gravitational force acts on (you guessed it) mass. It's the force that keeps planets in orbit. It's range is, like the electromagnetic force, infinite. The gravitational force is relatively weak though and unless you're an english teacher, we tend to find that people don't get attracted to each other simply because they (or we?) don't have enough mass. The gravitational force's exchange particle is the theoretical 'graviton' which has yet to be discovered. So - what does the standard model look like?It looks like this:
Hope this helped!I'm planning on completing this topic on here with more on Feynman diagrams etc later on, let me know if there are any mistakes, if you have any questions or if you want me to write up certain topics for you! Over and out :)
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AuthorI'm a 17 year old student who has a huge passion for science! Categories |