AQA AS PHYSICS QUANTUM PHENOMONA
LATEST UPDATE
What is the photoelectric effect?
Emission of electrons from a surface when a surface is illuminated by light of a
frequency greater than the minimum value known as the threshold frequency.
Photoelectric emission does not take place if ___________________
the frequency of the incident electromagnetic radiation is below a certain value known
as the threshold frequency.
The number of electrons emitted is ____________
proportional to the intensity of the incident radiation, provided the frequency is greater
than the threshold frequency.
Photoelectric emission occurs without delay as soon as _______
incident radiation is directed at the surface, provided the frequency of radiation exceeds
the threshold frequency.
When light is incident on a metal surface _____________
An electron at the surface absorbs a single photon from the incident light and therefore
gains energy equal to hf.
An electron can leave the metal surface if _____________
The energy gained from a photon exceeds the work function of the metal.
Define work function.
minimum energy needed by an electron to escape from the metal surface.
Excess energy gained by an electron beccomes _______________
Its kinetic energy.
Emission can take place from a metal surface provided ________________
Ekmax>0 or hf>0
Electrons that escape from the metal plate can be attracted back to it by
______________
giving the plate a sufficient positive charge.
What is the stopping potential?
The minimum potential needed to stop photoelectric emission.
At stopping potential, the maximum kinetic energy is ________________
reduced to zero because each electron must do extra work equal to e x Vs
When a conduction electron absorbs a photon ______________
its kinetic energy increases by an amount equal to the energy of a photon.
If the energy of the photon exceeds the work function of the metal ____________
The conduction electron can leave the metal.
If the electron does not leave the metal ______________
it repeatedly collides with other electrons and positive ions and it quickly loses its kinetic
energy.
When light of a frequency greater than the threshold frequency for the metal is
directed at the photocathode ______________
LATEST UPDATE
What is the photoelectric effect?
Emission of electrons from a surface when a surface is illuminated by light of a
frequency greater than the minimum value known as the threshold frequency.
Photoelectric emission does not take place if ___________________
the frequency of the incident electromagnetic radiation is below a certain value known
as the threshold frequency.
The number of electrons emitted is ____________
proportional to the intensity of the incident radiation, provided the frequency is greater
than the threshold frequency.
Photoelectric emission occurs without delay as soon as _______
incident radiation is directed at the surface, provided the frequency of radiation exceeds
the threshold frequency.
When light is incident on a metal surface _____________
An electron at the surface absorbs a single photon from the incident light and therefore
gains energy equal to hf.
An electron can leave the metal surface if _____________
The energy gained from a photon exceeds the work function of the metal.
Define work function.
minimum energy needed by an electron to escape from the metal surface.
Excess energy gained by an electron beccomes _______________
Its kinetic energy.
Emission can take place from a metal surface provided ________________
Ekmax>0 or hf>0
Electrons that escape from the metal plate can be attracted back to it by
______________
giving the plate a sufficient positive charge.
What is the stopping potential?
The minimum potential needed to stop photoelectric emission.
At stopping potential, the maximum kinetic energy is ________________
reduced to zero because each electron must do extra work equal to e x Vs
When a conduction electron absorbs a photon ______________
its kinetic energy increases by an amount equal to the energy of a photon.
If the energy of the photon exceeds the work function of the metal ____________
The conduction electron can leave the metal.
If the electron does not leave the metal ______________
it repeatedly collides with other electrons and positive ions and it quickly loses its kinetic
energy.
When light of a frequency greater than the threshold frequency for the metal is
directed at the photocathode ______________
