particle physics Flashcards
what did j.j thompson propose?
the plum pudding model
at atom ocntiamed negative electrojs embedded in a uniform sea of positive charged dough.
rutherford experiment
a narrow beam of alpha particles were targeted at a thing piece of gold. they scattered and each alpha particle hitting hte flourescemt screen produces a speck of light
Observation 1
mos of the alpha particles passed straqight through the fold with little scattering
observation 1
very few alpha particles were deflected
conculsions
most of the atom was made up of empty space and th emost of the mass was concentrated in a space regioon- the nucleus.
the more energetic a alpha particle was…
the closer it got toward the nucleus
Nucleon
refers to a proton or neutron
z
atomic numberA
A
nucleon number/mass number
isotopes
nuclei of the same elemetn that have the same number of proton but different number of neutrons.
Atomic mass unit
one twelfth the mass of a neutral carbon-12 atom.
what is the radius of an nucleus dependent on?
the nucleon number
what adoes strong nuclear force acts between?
nucleons
what is the attractive force about?
3fm
what is the replusive force about?
0.5fm
if an antiparticle and particle meet what happens?
they annihilate each other and convert inot a high energy pair of photon
what is the charge and mass of a an antiparticle?
opposite charge of particle and same mass
what is the nitparticle of an electron?
positron
what is the range of stron nuclear forces?
very short ranged
what is weak nuclear force?
responsible for radioactivity particulary beta decay.
what is the range for weak nuclear forces?
10-18
what is electromagnetic forces?q
responsible ofr electricity and light.
wha is experiences electromagnetic forces?
static/ moving charged particles
what is gravitational forces?
binds us to the earth and orbits our planets.
what is the range for gravitational forces?
Infinite range
what are fundamental particles?
have no internal structure
protons?
not fundamental particle made of quarks
neutrons?
not fundamental particles made of quarks
electrons
fundamental particle
photon?
fundamental particle
neutrinos?
fundamental particle
leptons?
fundamental particleh
what are hadrons?
any particle that contains quarks
hat are hadrons affected by?
particles and antiparticles strong nuclear charge and if charged electromagnetic
how do hadrons decay?
from weak nuclear chargee
example of hadron?
proton, neutron and meson
what are leptons not affected by?
strong nuclear forces
what are leptons affected by?
gravitation, weak nuclear forces and if charged electromagnetic.
quarks of a proton?
uud
quarks of neutron?
udd
what are baryons?
any hadron made with a combination of three quarks
what are mesons?
hadrons made with a combination of quarksand antiquarks
what is the charge and mass of neutrinos?
no mass or charge
what are the three types of neutrinos?q
electron
muon and
tau
what is produced in the emission of alpha radiation?
helium nuclei
what is produced in the emission of beta radiation
electron or positron
what is produced in the emission or gamma radiation?
high energy gamma rays
what happens in beta minus decay?
neutron decays into prodton and eleycon and electron neutriono
what does beta plus produce?
proton decays into neutron, positron and electron neutrino
down quark decay
down quark–> up quark + electron + electron antineutrino
up quark decay?
up quark–> down quark+ positiron+ electron antineutrino
