Wave-Particle Duality Flashcards Preview

Higher Physics > Wave-Particle Duality > Flashcards

Flashcards in Wave-Particle Duality Deck (16)
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1
Q

what is the photoelectric effect evidence for?

A

the particle model of light

2
Q

examples of light as a a wave

A
  • refraction
  • reflection
  • interference
3
Q

example of light as a particle

A

the photoelectric effect

4
Q

what happens when white light is shone onto a metal plate?

A

white light photons do not exceed the threshold frequency and therefore the work function

5
Q

what happens when UV light is shone onto a metal plate?

A

electrons are released as the photons did exceed the threshold frequency

6
Q

relationship which combines energy of a photon and frequency

A

Ephoton=hf

7
Q

what is the only thing that affects the energy of a photon

A

the frequency of the photon

8
Q

what does increasing brightness do?

A

increases the number of photons, not their individual energy

9
Q

what would increasing brightness do if light was a wave?

A

release an electron

10
Q

Ephoton

A

no electron are freed

11
Q

Ephoton=Eo

A

electron freed but does not have sufficient kinetic energy to leave

12
Q

Ephoton>Eo

A

electron has sufficient kinetic energy to leave

13
Q

formulas to work out kinetic energy

A
  1. Ek=Ephoton-Eo
  2. Ek=hf-hfo
  3. Ek=1/2mv^2
14
Q

threshold frequency

A

minimum frequency of a photon required for photoemission.

15
Q

work function

A

minimum energy of a photon required to cause photoemission.

16
Q

graph of current against frequency

A

horizontal line across the x-axis until it reaches the threshold frequency. It then curves up with decreasing gradient.