A LEVEL 3 GCE PHYSICS COMPREHENSIVE
REVIEW SHEET QUESTIONS AND DETAILED
SOLUTIONS
●● Photo Electric Effect Model Answer
Answer: - 1 Electron near the surface of a metal gains 1 photon and
gains enough energy to be liberated
- The work function is the energy needed for the electron to escape the
surface
- increasing intensity will increase the number of photons
- increasing frequency will increase the energy of the photons
- These electrons released are called photoelectrons
- This effect can be explained through E = hf
●● PhotoElectric Equation
Answer: Ekmax = hf - work fucntion
,Ekmax = max kinetic energy of freed electrons
hf = energy of photon
work function = the minimum energy to release an electron
●● Why does the photoelectric effect equation refer to kinetic energy as
maximum kinetic energy?
Answer: It will not always be an equal energy transfer:
- Some energy may have been transferred to electrons below the surface
- Therefore for these electrons to liberate to the surface there will be heat
transfer through collision
- therefore the electrons leaves the surface will less than max
●● Energy Frequency equation
Answer: E = hf
E = energy
h = plank's constant
f = frequency
,●● Work function equation
Answer: Work Function = h x threshold frequency
●● Work Function
Answer: the minimum energy needed to liberate an electron from a
metal atom
●● Threshold Frequency
Answer: minimum light frequency necessary to liberate an electron from
a given metal
Energy is proportional to frequency
●● Wave Particle Duality Model Answer
Answer:
●● Nuclear Binding Energy
Answer: The energy needed to separate a nucleus into individual protons
and neutrons
E = mc^2
, Binding Energy = mass difference x the speed of light^2
●● How to calculate nuclear binding energy from a nuclear decay
equation?
Answer: Th -> Ra + a
Mass of Th nuclear-(Mass of Ra nuclear + mass of alpha particle)
Convert u to kg
Multiply by speed of light^2 E = mc^2
Convert to Mev
●● How to convert u to kg
Answer: kg / 1.6605x10^-27
●● How to convert kg to u
Answer: kg / 1.6605x10^-27
●● What is 1 u?
Answer: 1.6605x10^-27kg
REVIEW SHEET QUESTIONS AND DETAILED
SOLUTIONS
●● Photo Electric Effect Model Answer
Answer: - 1 Electron near the surface of a metal gains 1 photon and
gains enough energy to be liberated
- The work function is the energy needed for the electron to escape the
surface
- increasing intensity will increase the number of photons
- increasing frequency will increase the energy of the photons
- These electrons released are called photoelectrons
- This effect can be explained through E = hf
●● PhotoElectric Equation
Answer: Ekmax = hf - work fucntion
,Ekmax = max kinetic energy of freed electrons
hf = energy of photon
work function = the minimum energy to release an electron
●● Why does the photoelectric effect equation refer to kinetic energy as
maximum kinetic energy?
Answer: It will not always be an equal energy transfer:
- Some energy may have been transferred to electrons below the surface
- Therefore for these electrons to liberate to the surface there will be heat
transfer through collision
- therefore the electrons leaves the surface will less than max
●● Energy Frequency equation
Answer: E = hf
E = energy
h = plank's constant
f = frequency
,●● Work function equation
Answer: Work Function = h x threshold frequency
●● Work Function
Answer: the minimum energy needed to liberate an electron from a
metal atom
●● Threshold Frequency
Answer: minimum light frequency necessary to liberate an electron from
a given metal
Energy is proportional to frequency
●● Wave Particle Duality Model Answer
Answer:
●● Nuclear Binding Energy
Answer: The energy needed to separate a nucleus into individual protons
and neutrons
E = mc^2
, Binding Energy = mass difference x the speed of light^2
●● How to calculate nuclear binding energy from a nuclear decay
equation?
Answer: Th -> Ra + a
Mass of Th nuclear-(Mass of Ra nuclear + mass of alpha particle)
Convert u to kg
Multiply by speed of light^2 E = mc^2
Convert to Mev
●● How to convert u to kg
Answer: kg / 1.6605x10^-27
●● How to convert kg to u
Answer: kg / 1.6605x10^-27
●● What is 1 u?
Answer: 1.6605x10^-27kg
