Quantum and Nuclear Physics Flashcards
Photon
A discrete packet of energy of electromagnetic radiation
Energy of one photon = Planck constant x frequency
The photoelectric effect
the emission of electrons when electromagnetic radiation of high enough frequency is incident on a metal surface
work function energy
the minimum energy of a photon needed to cause emission of electrons from the surface of the metal
threshold frequency
the minimum frequency of electromagnetic radiation to cause emission of electrons from the surface of a metal
threshold wavelength
the maximum wavelength of electromagnetic radiation to cause emission of electrons from the surface of the metal
Stopping potential
the minimum potential difference
between the emitting metal and the collector that prevents the most energetic photoelectrons from reaching the collector plate, resulting in zero photoelectric current
evidence of electromagnetic radiation acting like particles
emission of electrons only when electromagnetic radiation is above a minimum threshold frequency regardless of intensity
Maximum kinetic energy of emitted electrons is affected by the frequency of electromagnetic radiation but independent of intensity
instantaneous emission of electrons when electromagnetic radiation is above a minimum frequency even for low intensity
absorption line
a continuous spectrum crossed by dark lines
emission line
discrete bright lines of different colours on a dark background
De Broglie wavelength
wavelength associated with a particle that is moving
Heisenberg Uncertainty
if a measurement of position is made with uncertainty and a simultaneous measurement of momentum is made with uncertainty, the product of the uncertainties can never be smaller than the Planck constant
