what is a photon?
packet of energy of quantised values
what is the equation to work out the energy of a photon?
energy (J) = planck constant (Js) x frequency of light (Hz)
which wave in the electromagnetic spectrum has the highest frequency?
gamma
which waves are ionising?
- ultraviolet
- x-ray
- gamma
what is the equation of momentum from KE?
p = √2m(KE)
what is the charge of a photon?
neutral
how do we prove that electrons travel as waves?
- diffraction and interference of electrons
- wavelength of electrons is comparable to size of carbon atom
what is the photoelectric effect?
emission of electrons from the surface of a metal when an EM waves are incident on the metal
what is the threshold frequency?
minimum frequency of wave required to emit an electron from the surface of a metal
what changes from a photon in different materials?
- wavelength
- velocity
- direction
what remains constant of a photon in different materials?
- frequency
- energy
how to work out number of photons emitted per second?
power/energy
what is an electronvolt?
energy gained by an electron when travelling from rest through a potential difference of 1V
