modern physics Flashcards
what unit is eV measured in
joules
what are the two main ways electrons can be emitted
thermionic or photoelectric
what is the work function?
energy needed to allow electron to leav surface
what is a photon
a particle of light
how does intensity of light affect the photelectric effect
affects number of electrons that can leave
how does frequency of photon affect photoelectric effect
whethet an electron can leave and with what kinetic energy
what are alpha particles made of
helium nucleus of 2 protons and 2 neutrons
what happens when an electrin falls back to its original level
it releases the excess energy as a light frequency
where is a beta particle ejected from
the nucleus, a neutron breaks into 2 parts and releases the megative component(electron)
what is a gamma ray
EM radiation
how do you demonstrate the prentrating ability of radiation
how do you demonstrate the ionising ability of radiation
set up a charged electroscope
hold radioactive source near cap
alpha will cause biggest fall of leaf, beta will have a bit less effect and gamma will have little to none
thus proving larger radiation particles knock more electrons off
what is nuclear fission
the splitting of a nucleus into two smaller nuclei with release of neutrons and energy
what is chain reaction
a fission reaction where an emotted neutron carries on reaction
what is critical mass?
the minimum mass of FISSILE MATERIAL to carry on chain reaction
