The Simple Atomic Model and Unanswered Questions

Our understanding of the design of the atom changed radically in the 50 years that I taught chemistry in public school. When I started teaching, scientists thought atoms were made up of a nucleus surrounded by electrons in circular orbits. This simple atomic model was easy to understand, and we had drawings and even plastic models to show it. However, the simple atomic model leaves unanswered questions. 

The simple model did not explain the properties of certain atoms. For example, why is mercury a liquid at room temperature while other metals, such as gold, platinum, and lead, are solids, even though they have very similar structures? Why are gold and silver different colors? Why does water expand when it gets colder when all other materials contract? 

As an old chemistry teacher, my students frequently asked questions I could not answer. Improvements in spectral analysis made the simple atomic model more complicated while answering some questions. For example, scientists could see that not all electrons travel in circular orbits. Also, electrons are not solid balls or even particles. Instead, electrons can be waves and have orbital paths that are spherical or shaped like dumbbells, clover leaves, or a mixture of those two. 

Different orbital shapes cause different spectral patterns. As a result, scientists have coined the names “s” for sharp spectral lines, “p” for principle lines, “d” for diffuse lines, or “f” for fundamental lines. Moving out from the nucleus of an atom, the number of electrons increases, and their paths become more complex. 

The more we learn, the more we see the wisdom built into the design of every atom in the universe. The precision of design makes it possible for life to exist. Minor changes would mean that we would not be here. However, the simple atomic model leaves unanswered questions and can’t begin to show the extent of God’s design wisdom. Applying what we know about relativity, quantum mechanics, and electron orbits answers some of the chemistry students’ difficult questions. We will have more on that tomorrow.

— John N. Clayton © 2023

Reference: “Relativity and the World of Molecules” by Abhik Ghosh and Kenneth Ruud in American Scientist magazine for May/June 2023