Quantum
Definitions:
• Threshold frequency – minimum photon frequency that will cause
photoelectrons to be released. At f0, Ek = 0, therefore f0 = 0/h
• Work function – minimum amount of energy required to liberate an electron from
the surface of the metal. Each metal has its own work function.
• Ek(max) – maximum kinetic energy of the photoelectrons.
• Ionisation – completely gaining/removing an electron from an atom to become
an ion.
• Ion – a charged particle.
• Ionisation energy – energy required to remove an electron from the ground state.
• Excitation – electron absorbs exact amount of energy (for the difference between
the two energy levels) and moves to a higher energy level
• De-excitation – from the temporary excited state, electron emits a photon (for the
difference between the two energy levels) and falls to a lower energy level
• Photoelectric effect – emission of electrons when light shines on a material.
• Stopping potential – potential is increased to the point when the emitted
electrons have zero kinetic energy.
• Photon – packet of light energy.
• Photoelectron – electron that was emitted from a material when it absorbs light.
• De Broglie wavelength – wavelength of a moving particle.
Threshold frequency
Photoelectrons have a range of kinetic energies because electrons closer to the surface
will have maximum kinetic energy, electrons further away from the surface will have
less kinetic energy as they lose it travelling up.
Definitions:
• Threshold frequency – minimum photon frequency that will cause
photoelectrons to be released. At f0, Ek = 0, therefore f0 = 0/h
• Work function – minimum amount of energy required to liberate an electron from
the surface of the metal. Each metal has its own work function.
• Ek(max) – maximum kinetic energy of the photoelectrons.
• Ionisation – completely gaining/removing an electron from an atom to become
an ion.
• Ion – a charged particle.
• Ionisation energy – energy required to remove an electron from the ground state.
• Excitation – electron absorbs exact amount of energy (for the difference between
the two energy levels) and moves to a higher energy level
• De-excitation – from the temporary excited state, electron emits a photon (for the
difference between the two energy levels) and falls to a lower energy level
• Photoelectric effect – emission of electrons when light shines on a material.
• Stopping potential – potential is increased to the point when the emitted
electrons have zero kinetic energy.
• Photon – packet of light energy.
• Photoelectron – electron that was emitted from a material when it absorbs light.
• De Broglie wavelength – wavelength of a moving particle.
Threshold frequency
Photoelectrons have a range of kinetic energies because electrons closer to the surface
will have maximum kinetic energy, electrons further away from the surface will have
less kinetic energy as they lose it travelling up.
