You have certainly seen the type of bright, colorful signs shown in the picture above. Have you ever looked closely at a neon sign and wondered what causes them to glow the way that they do? It’s all about electrons! In the last chapter, Atomic Structure, you learned about some of the earliest atomic models and how they changed over time, ending with the important discovery of the nucleus of the atom by Ernest Rutherford. In this chapter we focus on the electrons. Where are they located? What are their energies? How do they move? Along the way, we will learn about the complex arrangements of electrons in the atoms of each and every element as well as about how the gases contained in a neon sign emit their bright light.
Opening image by Chip Griffin. www.flickr.com/photos/chipgriffin/2210297177/. CC-BY 2.0.