Photo electric effect

[Rachel Brown 3A]

What is the point of determining the threshold amount of light that causes the electrons to be emitted? Why do we focus on the photo electric effect/what does it teach us about the quantum world?

[Chem_Mod]

I will cover this in detail in Wednesday's class.

Others can add their comments in answering these questions.

[Emma Miltenberger 2I]

The photoelectric effect is highly important because it demonstrates that light has both wave and particle characteristics. Before the photoelectric experiment, light was largely regarded as being a wave and was modeled as a wave in the scientific world. However, the photoelectric effect demonstrated that increasing the intensity of a light source will not cause more electrons to be emitted. This showed that light was acting as pockets of particles instead of a wave. The threshold amount or work function, shows how much energy is required to emit an electron from a specific metal. It helps us better understand how light works and what is happening on a quantum scale.

[Yixin Angela Wang 2H]

I'll just add some things that Dr. Lavelle covered in lecture today. The photoelectric experiments showed that light can behave like a wave, and the properties of light, specifically the effects of increasing its intensity, change when light is thought of as particles. In wave form, light's energy increases with intensity because the amplitudes of the waves increase. However, in particle form, only the number of photons increases with intensity, not the energy that each photon carries. Thus, if one frequency of light is too weak to cause a metal to emit electrons, increasing intensity will not work.