Students using the wave model of light attributed the photoelectric effect to vibrations caused by wavefronts striking the metal
They thought that electromagnetic waves that hit the metal surface vibrate the electrons on the surface and thus transfer their energies to the electrons and enable them to become free. They also thought that an increase in light intensity would lead to an increase in the number of wavefronts and photoelectrons.
Resources to Address This
Use this lesson outline to help plan and carry out a practical demonstration of the photoelectric effect. The outcomes of the experiment are discussed along with an analogy leading to the idea of electrons requiring sufficient energy to escape a potential well and the corresponding equation.
A worksheet providing questions about the photoelectric effect is also linked.View Resource
These videos cover a wide range of approaches to teaching area of quantum and nuclear physics.
The “Photoelectric effect” video demonstrates the effect using an electroscope and then discusses the effect in detail using Lego to give an interesting visual approach. This can be used to explain the effect before moving on to the equation.
After the video, discuss how a wavefront could not account for energy being received by individual electrons in a way which would allow them to escape the potential well.View Resource
A discussion of how frequency and energy delivered by photons is related. Use this to help explain why low frequency (low energy) photos are unable to cause the photoelectric effect even when light intensity is high.View Resource
- Özcan, Ö., () Investigating students’ mental models about the nature of light in different contexts, European Journal of Physics, 32, 065042,