, AQA A LEVEL PHYSICS PAPER 1 EXAM
QUESTIONS AND ANSWERS 100%
CORRECT!
What is meant by work function (2) - ANSWER Minimum energy required by an electron
to escape from (1) a metal surface (1)
What is meant by ionisation energy? (2) - ANSWER Minimum energy required to
remove an electron from an atom (1) from the ground state (1)
Why do emitted electrons have a kinetic energy that varies up to a maximum value? (4)
- ANSWER Energy of a photon is fixed/constant (1)
Energy is required for electrons to overcome work function ø (1)
Electrons deeper into/below the surface of the metal require more energy to overcome
work function and therefore have less KE(1)
Maximum KE = Energy of photon - work function ø (1)
Explain how (bright ring) diagram is evidence of the wave-particle duality of electrons? -
ANSWER Diffraction pattern maxima/minima (bright and dark areas) (1)
Diffraction is a property of waves- proves wave-behaviour of electrons (1)
What is meant by the ground state? - ANSWER The lowest energy state of an atom
Explain the difference between excitation and ionisation (2) - ANSWER An electron
receives a discrete amount of energy for BOTH (1)
Excitation promotes an electron to a higher energy level
Ionisation is when an electron receives enough energy to leave the atom
Explain why only photons of certain frequencies cause excitation (4) - ANSWER
discrete energy levels (1)
Electrons need to absorb a DISCRETE amount of energy to move to a higher energy
level (1)
Photons need to have a certain frequency to provide this energy, because E=hf (1)
interaction is a 1:1 reaction all of the photon's energy is absorbed (1)
QUESTIONS AND ANSWERS 100%
CORRECT!
What is meant by work function (2) - ANSWER Minimum energy required by an electron
to escape from (1) a metal surface (1)
What is meant by ionisation energy? (2) - ANSWER Minimum energy required to
remove an electron from an atom (1) from the ground state (1)
Why do emitted electrons have a kinetic energy that varies up to a maximum value? (4)
- ANSWER Energy of a photon is fixed/constant (1)
Energy is required for electrons to overcome work function ø (1)
Electrons deeper into/below the surface of the metal require more energy to overcome
work function and therefore have less KE(1)
Maximum KE = Energy of photon - work function ø (1)
Explain how (bright ring) diagram is evidence of the wave-particle duality of electrons? -
ANSWER Diffraction pattern maxima/minima (bright and dark areas) (1)
Diffraction is a property of waves- proves wave-behaviour of electrons (1)
What is meant by the ground state? - ANSWER The lowest energy state of an atom
Explain the difference between excitation and ionisation (2) - ANSWER An electron
receives a discrete amount of energy for BOTH (1)
Excitation promotes an electron to a higher energy level
Ionisation is when an electron receives enough energy to leave the atom
Explain why only photons of certain frequencies cause excitation (4) - ANSWER
discrete energy levels (1)
Electrons need to absorb a DISCRETE amount of energy to move to a higher energy
level (1)
Photons need to have a certain frequency to provide this energy, because E=hf (1)
interaction is a 1:1 reaction all of the photon's energy is absorbed (1)
