What is the colour of an electron?

Let’s begin with the question: How do we perceive color? When we receive light, our eyes measure its intensity and very roughly its wavelength. It is rare to see monochromatic light. Instead, we often see a mix of different wavelengths. Our eyes are able to see one particlular mixture. This is when the proportions of different wavelengths are identical, such as natural sunlight. It is called neutral or white. If you see an object that scatters or reflects light and it does so in the same way as natural sunlight, you will be able to see its colour as neutral. If you see a colored object, it means that it reflects a wavelength stronger than the others. Therefore, the wavelengths of light reaching your eyes have a different wavelength composition, so you will see it as coloured.

How does it work with electrons? Do they all reflect the same wavelengths? Well, it depends. They can only absorb and reflect certain wavelengths if they are bound to atoms or molecules. This is how you see most of the colours in objects around you: electrons bound to dye molecules scatter certain wavelengths of light.

Does this mean electrons can have colour? It does not, as the same electron could be bound in different molecules, producing different colours. We must therefore remove electrons from any molecular or atomic bonds to answer this question and see a free electron.

You would only see one free electron, but you can look at many electrons almost every day by looking at mirrors or metallic surfaces. The atoms of a metal are found in crystal lattices. Although most electrons are bound to atoms, some electrons (those in the outermost electron layers), can freely roam through the crystal. Their interaction with light is similar to how free electrons interact. As you can see, the mirror reflects white light, which means that electrons remain colour neutral.

Yes, you may be asking about gold. It is not neutral, but yellow. This does not mean that electrons in gold have “yellow” hues. The reason gold isn’t white lies in electrons that aren’t free but are still bound to the gold atoms. Although the free electrons found in gold are able to reflect all colours of light as other metals, the atoms of the gold can absorb some blue light so that less blue light is reflected, which results in yellow.

Leave a Comment