Transfer equation?
eV = 1/2 mv²
Units of planck constant?
Js^-1
Equation for energy of a photon?
E = hf
Formula for the kinetic energy for a photoelectron?
W=eV
eg. pd: 15V Ke: 5eV
What is the photoelectric effect?
when a photoelectron is emitted when a metal is exposed to photons of electromagnetic radiation.
What is the work function?
The minimum energy needed to remove a single electron from the surface of a particular metal
What is threshold frequency?
The minimum frequency of the EM radiation that will cause the emission of a photoelectron from the surface of a particular metal
The Photoelectric effect explained.
- Photons of light (often UV) are incident on a metal (often zinc)
- These photons are absorbed in individual electrons int the surface
- It is a one to one interaction
- The electrons need to have absorbed enough energy to overcome the work function of the metal
What would be the effect of changing intensity when experimenting with photoelectrons?
Larger number of photons incidence per second
What is maximum KE?
eV = KEmax.
Formula for work function?
hf = φ + KEmax.
What is the de Broglie Wavelength?
The wavelength associated with a particle of mass, it is dependant of momentum
What is the formula for the de Broglie Wavelength?
λ = h/p
Describe a piece of evidence for believing that electrons can behave like waves
Electrons can be diffracted by a thin layer of graphite to create diffraction rings on a florescent screen
