by Ian Phillips ’23

The Rutherford-Bohr model, taught in school, depicts a hydrogen atom, centered around a nucleus and surrounded by electrons. However, this model is fundamentally opposed to the actual and more scientific models scientists use today.

Most students learned the Rutherford-~~ ~~Bohr model, as it’s the most basic and simple model to explain where electrons and nuclei are on an atomic scale. If you asked someone to draw an atom, their picture would likely reflect the Rutherford- Bohr model. But this model is misleading and has been disproven since 1927. Today, scientists and physicists use the Quantum Mechanical Model to explain and mathematically portray the atom. However, before anyone can understand the Quantum Mechanical Model, they need to know a little bit more about quantum mechanics, wave functions, and the Heisenberg Uncertainty Principle.

As some may know, the world is not often black and white, good and evil. More often than not, a coin flip is not 50/50, as there are innumerable factors that can decide the outcome of the coin flip. The same goes for quantum particles. When looking at an atom there is no saying “The electron is either there or it is not.” Rather, someone can only truly determine the probability of the particle being there at one time, when this particle is in a quantum state. Quantum states can be expressed through quantum mechanics, and quantum particles can be located and observed through wave functions. In a wave function, the location or state of a particle is measured through probability amplitude or Ψ^2. All of this is to say that nobody knows the behavior of an electron, a photon, etc. So made-up or complex numbers are used to explain them.

At this point, the reader may be asking themselves, “Why is the Rutherford-Bohr model wrong?” Three words: Heisenberg Uncertainty Principle. This principle states that “…We cannot know both the position and speed of a particle, such as a photon or an electron, with perfect accuracy; the more we nail down the particle’s position, the less we know about its speed and vice versa” (Caltech). This means that while quantum particles exist, no one can tell where and how fast they are moving. Thus, the Rutherford-Bohr Model is inaccurate and not at all representative of the atom’s true nature, since the model clearly defines the quantum particles on a 2D plane at static points. To express this interaction, quantum physicists use the Quantum Atomic Model. This model displays a field of probability of the location of the quantum particles in the atom.

While the basics of subatomic particles and atoms are being taught in school, they are often wrong and misleading to inquisitive learners. The Quantum Model and the more accurate Probabilistic Model should replace the outdated Rutherford-Bohr model. Not only does the Quantum model portray a more realistic version of the atom, but it also introduces the basics of quantum mechanics and the mathematics working in the background of our universe.

Bibliography:

*What is the uncertainty principle and why is it important?* Caltech Science Exchange. (n.d.). Retrieved May 11, 2022, from https://scienceexchange.caltech.edu/topics/quantum-science-explained/uncertainty-principle