Studied by 5 people
isotope
same proton diff neutron
strong nuclear force (snf)
counteract electrostatic repulsion and acts on neutrons in small range
unstable
too many p n pn
alpha decay
too many p n
beta minus
too many n → proton electron antineutrino
neutrinos
conserve momentum
antiparticle
same rest energy and mass diff everything else
photon
packets of em radiation that transfer energy but no mass
annihilation
particle antiparticle collide releasing 2 photons in opposite directions
use of annihilation
pet scans release positron in body detect gamma photons
pair production
photon converted into matter and antimatter if ephoton > rest ebothparticles
exchange particles
carry energy and momentum between force experiencing particles
weak force
wbosons 3×10-18 all particles
weak force
wbosons 3×10-18 all particles
electromagnetic
virtual photons infinite charged particles
weak nuclear force (wnf) interactions
beta decay electron capture proton electron collision
electron capture
when particle has too many p p + inner electron → neutron and neutrino
Beta plus decay
proton → neutron + positron + neutrino
beta plus decay
proton → neutron + positron + neutrino
beta minus decay
neutron → proton +electron +anti neutrino
photoelectric effect
photoelectrons emitted from a metals surface after a light above a certain frequency is shone onto it
what does photoelectric effect prove
light is a particle
working function
min energy for electron to be emitted from metal surface
stopping potential
pd to apply across metal to stop photoelectrons with ekmax
what is the use of stopping potential
find ekmax of released photoelectrons
excitation
electrons move up a discrete energy level after gaining energy
ionisation
the electron is removed from the atom if eelectron>eionisation
after excitation
electron returns to original level and energy is released as a photon if e = energy level difference
flourescent tube
low pressure mercury vapour → electron collide with atoms →excite mercury atoms→ dexcite uv photons→ excite tube coating →dexcite releasing visible light photons
1eV
energy gained by 1 electron when passed through a pd of 1V
line spectrum
after light through diffraction grating each line diff wavelength of light
line absorption spectrum
continuous spectrum with black lines at wavelengths
light as particle
photoelectric effect
light as wave
diffraction
momentum changes
changes amount of diffraction
leptons
fundemental dont experice snf
hadrons
made of quarks
baryons
3 quarks
quark composition of protons
uud
quark composition of neutrons
udd
mesons
quark antiquark pair
proton
only stable baryon
strange particles
produced by snf decay by wnf
Note 
Flashcard (68)