Explaining light properties
There are some properties of light which can only be explained by certain models.
There are two main models of light:
- The wave model
- The particle (photon) model
They can’t each explain everything, but together, they can:
| Property | Wave model | Particle model |
|---|---|---|
| Reflection | The light waves themselves are reflected | The photon particles are reflected at the surface |
| Refraction | The light waves slow down and bend towards or away from the normal | The particles are just refracted at the surface |
| diffraction | Waves spread out when they pass through a gap | Cannot explain it |
| Interference | Waves superpose and their amplitudes add together at each point. | Cannot explain it |
| polarisation | The direction of oscillation occurs in a certain | Cannot explain it |
| Photoelectric effect | Cannot explain it | The electrons have a threshold frequency based on their work function. |
This shows that maybe light (and other waves and particles) aren’t just one or the other, but both - this is wave particle duality.
flashcards
| Question | Answer |
|---|---|
| Reflection (Wave model) | The light waves themselves are reflected |
| Reflection (Particle model) | The photon particles are reflected at the surface |
| Refraction (Wave model) | The light waves slow down and bend towards or away from the normal |
| Refraction (Particle model) | The particles are just refracted at the surface |
| Diffraction (Wave model) | Waves spread out when they pass through a gap |
| Diffraction (Particle model) | Cannot explain it |
| Interference (Wave model) | Waves superpose and their amplitudes add together at each point. |
| Interference (Particle model) | Cannot explain it |
| Polarisation (Wave model) | The direction of oscillation occurs in a certain direction |
| Polarisation (Particle model) | Cannot explain it |
| Photoelectric effect (Wave model) | Cannot explain it |
| Photoelectric effect (Particle model) | The electrons have a threshold frequency based on their work function. |
| What are the two main models of light? | The wave model and the particle (photon) model |
| Which model of light explains diffraction? | The wave model |
| Which model of light explains the photoelectric effect? | The particle (photon) model |
| What term describes the idea that light is both a wave and a particle? | wave particle duality |