Preparation - Chapter 1.1a, Chapter 1.1b
Participation - Assignment P.8 Q7-10 and P.41 Q26, 30
Presentation - Blackboard, Student's Work
Possession
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Preparation - Chapter 1.2a, b, b2 , c, c2(Threshold frequency), c3(no time delay), c4(I-V relationship), c5 (example 1), c6 (Intensity of light), c7 (Failure of wave theory)
Participation - Assignment P.18 Q6, 8 and P.41 Q22, 27
Presentation - Blackboard, Student's Work
Possession
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Preparation - Chapter 1.3a, Chapter 1.3b, Chapter 1.3c
Participation -
Assignment 3A
P.33 Q10-14 and P.41 Q23, 24, 28, 29, 25
Assignment 3B
P.41 Q31-39
Presentation - Blackboard, Student's Work
Possession
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What wave theory assumes? And why it cannot explain photoelectric effect?
According to wave theory, wave is a continuous form of energy, its energy is determined by its amplitude only (but not frequency).
According to wave theory, an electron can ALWAYS absorb enough energy to escape from a metal surface if ENOUGH time is given. However, it is not the case. The incident wave must have a HIGH ENOUGH FREQUENCY and it takes NO TIME to have an electron to emit.
According to photon theory, light is wave packet.
An electron may absorb a photon in no time. If the energy of photon (E = hf) is high enough, the photon is absorbed and the electron is emitted. However, an electron can only absorb one photon only.
LASTLY, the maximum KE of photoelectron is limited in photoelectric effect experiment as Kmax = hf-W (W is work function of the metal surface). In wave theory, however, Kmax should increase with intensity (or amplitude) of the wave, and of course, wave theory is wrong.
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