AQA A LEVEL PHYSICS PAPER 1 ACTUAL
EXAMINATION QUESTIONS WITH
CORRECT ANSWERS GRADED A+
⫸ 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)
⫸ Explain how excitation takes place in a fluorescent tube Answer:
Electrons flow through the tube to the applied PD causing a current to
flow (1)
Electrons collide with mercury atoms in the tube (1)
This raises electrons in the mercury atom to a higher energy level (1)
⫸ What is the purpose of coating in a fluorescent tube? Answer: UV/
High energy photons emitted from mercury atoms when the electrons in
the atom de-excite (1)
High energy photons absorbed by the coating (1)
Coating emits photons in the visible spectrum (1)
EXAMINATION QUESTIONS WITH
CORRECT ANSWERS GRADED A+
⫸ 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)
⫸ Explain how excitation takes place in a fluorescent tube Answer:
Electrons flow through the tube to the applied PD causing a current to
flow (1)
Electrons collide with mercury atoms in the tube (1)
This raises electrons in the mercury atom to a higher energy level (1)
⫸ What is the purpose of coating in a fluorescent tube? Answer: UV/
High energy photons emitted from mercury atoms when the electrons in
the atom de-excite (1)
High energy photons absorbed by the coating (1)
Coating emits photons in the visible spectrum (1)
