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.
