Waves and Radiation Flashcards
How many fundamental Particles are there and what do they make up
12 and they make up everything
what are they also known as and what 2 groups can they be split into.
Fermions
- Quarks
- Leptons
how many types of quarks are there
To 1st generation called up and down
– These make up protons and neutrons
To 2nd generation called charm and strange
two 3rd generation called top and bottom
Explain what you know about hadrons
Greek for massive
these are Particles made up of quarks
Bayrons – these are made up of three quotes
Mesons –these are made up of a quark and an antiquark pair
Explain what you know about Bayrons
Examples include the proton and a neutron
Proton consists of two up and one down quark which equals 1e
neutron consists of two down on one up quark which equals 0e
Explain how you know about mesons
they are made up of a quark and an antiquark pair
because of the stairs very unstable
a pion pi+ made of a quark and antiquark pair
Pi+ charge equals 2/3+1/3=1e
Explain what you know about Leptons
they are fundamental particles
first generation lepton is electron (-ve)
second generation is muon (-ve)
Third generation is tau (-ve)
all leptons have associated anti particle
both leptons and anti particles have its own neutrino
what is the strong force
short range force that hold particles with the same charge together
it holds quarks together to form hadrons
its exchange particles are called gluons because they glue quarks together
the force is so strong that it can overcome the repulsion between the protons in the nucleus
what is the weak force
involved in radioactive, beta decay as the weak force is responsible for ‘flavour change’ which is the neutron turning into a up quark
exchange particles are called w and z bosons
extremely short force range only acting within the hadron
what is the electromagnetic force
this stops electrons from flying out of the atom and its exchange particle is the photon
what is radioactive decay
the breakout of the nucleus to release energy and matter
this allows the unstable nuclei to become stable
what three types of radiation can be emittedd
Alpha
Beta
Gamma
what is the nature of alpha and beta particles and gamma rays
alpha- helium nucleus
beta- fast electron
gamma ray- high frequency EM wave
what is alpha decay
when a nucleus undergoes alpha decay the mass number decreases by 4 (top) and the atomic number decreases by 2 (bottom)
what is beta decay
when this occurs the mass number is unchanged (top) the atomic number increases by 1
what is gamma decay
this can occur after either alpha or beta decay
gamma decay is responsible for removing left over energy from within the nuclei
what is nuclear fission
the breaking up of a large nucleus into two smaller nuclei
what are the two types of fission
spontaneous - a nucleus breaks down without any external influence (happens with heavy unstable man made isotopes)
induced fission- a nucleus breaks down after being bombarded with a neutron, this takes place in a reactor
what is nuclear fusion
the joining of two smaller nuclei to form a large nucleus
fusion powered stars is the method by which all of the elements in the universe were formed.
this happens all the time in stars at very high pressures and temperatures these conditions overcome repulsive forces between the nuclei and force them together
how to calculate the energy released is fission and fusion reactions
e=mc2 total the lhs mass total the rhs mass subtract lhs from rhs to get the mass lost sub into e=mc2 DO NOT ROUND TILL THE END
what is a chain reaction
when fission takes place neutons are released, these neutrons can collide with other nuclei and cause further fission reactions to take place and can go on forever.
