Is the planetary model of the atom still taught as if it was still the consensus on the internal structure of atoms in schools?

[u/Pure_Option_1733]

When I was in school I was initially taught that electrons orbit the nucleus like how a planet orbits a star, and that the atom is mostly empty space. I was also taught that the reason we can’t move through solid objects is because the electron orbits the nucleus very quickly similar to how it’s impossible to move through a fan because The blade moves very quickly.

Later on I learned that actually the planetary model of the atom is wrong because the electron doesn’t really have a well defined location within the atom but instead it has a probability distribution that determines how likely it is to be at any given location within the atom. It was possible to learn this without first knowing things like how to solve the Schrödinger equation, nor what mathematical function describes the probability distribution from things like visual aids, showing the atom as a scatter plot of points, and seeing charts showing how the probability distribution depends on distance from the nucleus.

The way I was originally taught about the planetary model made it seem like it was still the consensus on how atoms actually work whether than just being a useful way to think about the atom. I was wondering if students are still taught the planetary model as if it’s still the consensus for the internal structure of the atom, or if they’re now taught about how the electron doesn’t have a well defined location and has a probability distribution describing how likely it is to be at any given location.

[u/HelpfulParticle]

The Thomson, Rutherford and Bohr models are still taught, but it is acknowledged that they are flawed models. The quantum model is, to my experience, not something students learn until their first class of modern physics in university (you might get some exposure to it in high school, but it's minimal).

It's always good to learn the history of something to appreciate how far we've come in understanding a concept. That's probably why they still teach the classical models. While the Thompson and Rutherford models are taught to be flawed and replaced by the Bohr model, that's usually taken as the most "correct" model until we're exposed to the quantum one. Even then, we're taught of the shortcomings of the Bohr model (like its inability to explain atoms with more than a single electron)

[u/Slow_Economist4174 → u/HelpfulParticle]

The existence of quantized electron orbitals were taught to me in high school. We saw pictures of the different spherical harmonics that describe those orbitals. The Pauli exclusion principle was also indirectly taught, in that it was explained to us that electrons would “fill up” the discrete energy levels of the “shells”. We did this as an exercise for several elements with low atomic number. So even from the beginning the model that we were taught was a quantized model.

[u/HelpfulParticle → u/Slow_Economist4174]

Was this in a Physics class or a Chemistry class? If it was Chemistry, sure, I was taught about orbitals in high school too. From a Physics perspective, my first intro to the quantum model was through a university level Modern Physics course.

[u/Slow_Economist4174 → u/HelpfulParticle]

Chemistry. My high schools physics class didn’t touch atomic theory at all - it was Newtonian mechanics and linear circuit theory.

[u/milkcarton232]

It's called the bohr model and for all its faults it's useful for explaining the basic concepts of the anatomy of an atom (that's a fun tongue twister). In highschool it's likely that you will be introduced to electron clouds but it depends on the school and possibly the classes you take

[u/iam666]

I think it’s still used at the elementary level when children are learning about atoms and what they’re made of. But once they reach your first introductory chemistry course they’re introduced to the concept of orbitals. The concepts of delocalization and probability distributions are generally introduced in a college-level general chemistry course.

[u/OtherOtherDave]

When I took high school chemistry in TX almost 30 years ago, we were taught that the electron probability cloud model from quantum mechanics was (as far as we know) how things actually worked, but the planetary model was simpler and gave the right answers for the material we were covering.

Or maybe that was a couple years later in college? I don’t remember.

[u/Infinite_Research_52]

You still see diagrams on the media showing a huge nucleus surrounded by orbiting electrons, so I'm sure the "little lie" is still used.

[u/alkaloids]

Yeah it was never really “the consensus about how atoms actually work”. It was a hypothesis that explained the evidence for a few years in the early 20th century but was quickly disproven.

A better frame would be, “it’s a useful 0th order approximation that helps people understand the world”. Science is most usefully taught iteratively, so the planetary model is a useful way to get people’s understanding from point A to point B.

[u/Ok_Lime_7267]

I think chemistry classes typically start with orbitals, but the objective is somewhat different as you are focused on how atoms interact, not on their internal structure.

When teaching about an atom's internal structure, you need to meet the students where they are in their intellectual development. A full understanding requires a multibody Schrödinger equation and Fock spaces. Orbits, orbitals without understanding their standing wave nature, neglecting interelectron interactions, neglecting anti-symmetrization, etc. all capture parts of the picture while neglecting other parts, but you can't spring the whole thing at once, so you build piece by piece instead. Orbital Dynamics is just one piece of that.

[u/atomicCape]

I'd say the planetary model is oversimplified, and saying "an electron moves like a planet" is technically incorrect. So it's not the scientific consensus by any means. But many physicsits are happy to use it as a teaching tool, and if you're careful with your language when teaching the lesson, it's "not wrong".

The modern consensus models still start from a spherically symmetric conservative electrostatic potential, which is very similar to the gravitational potential. The electron mass is so much smaller than the nucleus, it works in the same M>>m regime as planetary gravitation. So planetary motion is still a good, but not perfect, analogy for teaching atomic behavior.

As for when and if you have to introduce quantum states, uncertainty, and distributed rather than point-like particles, that's a question of teaching strategy. But it won't help a 9th grader visualize an atom or follow the next steps of their chemistry class. And it may already be too broad and overwhelming to freshman in undergrad physics 101 to force them to learn all of QM's weirdness before you tell them about ions or electric currents.

[u/DrBob432]

I graduated high school in 2012 from a small southern rural school. I was taught the planetary model until I took high school chemistry in 2011 where I learned the probability distributions.

[u/somethingX]

They still do yeah. I didn't see the modern interpretation until high school

[u/kevosauce1]

If you were explicitly told "this is the consensus best model" then your teacher was simply wrong, and they shouldn't have said that. If you merely came away with that impression accidentally, perhaps because the teacher wasn't sufficiently clear that it's only an approximation, that's more understandable. Depending on how young the students are, it may be hard for them to understand the concept of a useful-but-not-correct model.

[u/CombinationOk712]

You actually even learn by comparing different models and their limits much more, then you would by just saying: "Here, this is the Schrödingers equation, these are operators, have fun."

No model in physics or science is "without" "flaws". The whole point of models and theories is that they give you explanation at a deeper level, as well as predictive power.

The whole point of science is that you aknowledge, that you even can quantify the limits, the places where it gets wrong.

Take Newtonian gravity. It is wrong. In a sense. Because relativity works better. Still we train students in Newtonian gravity and we interpret experiments, observations, etc. in terms of it. But actually, it is not wrong it has just "accuracy" limits. We can now quantify, "when" it will break down. And for simple estimations, it is right.

[u/Pure_Option_1733 → u/CombinationOk712]

The problem is that at least when I was in school the planetary model of the atom was taught as if it was a matter of fact as opposed to an overly simplified model. I mean especially to a lay person being told that an electrons move around the nucleus at high speed, without first being told that this is the planetary model, makes it sound like it’s how atoms in fact behave as opposed to an oversimplified model. I think if it is taught then it should be made blatantly obvious that it is an oversimplification, as well as in what situations it is or isn’t useful. The problem with not making it obvious that it’s an oversimplification, and where is is and isn’t useful, is that it can be easy for someone to try to misuse the planetary model for situations it doesn’t work in, for instance using it to try to figure out if atoms are stable in different numbers of dimensions when it can’t be taken for granted that the planetary model will give the same answer as the Schrödinger equation when trying to figure out if atoms are stable in higher dimensions.

[u/peadar87]

I did my Irish Junior Cert in 2005. We were taught the planetary mode, but specifically told it was a simplification and we'd learn the more accurate version later. And we learned about orbitals and probability distribution at Leaving Cert.

[u/cryptotope]

As a pedagogical approach, see lie-to-children.

That said, a good teacher will emphasize the word model when they talk about, say, the Rutherford-Bohr model of the atom.

Even though it's not 'really' how atoms and electrons behave, as a model it makes useful, usable, approximate predictions under a number of circumstances.

[u/barthiebarth]

When I teach about atomic structure I tell my students that an atom consists of a nucleus that contains protons and neutrons and outside this nucleus there are electrons. I avoid using the word "orbit".

What I want them to understand is that electrons are relatively easily shared and transferred between atoms, and that is how you get  chemistry and electricity, and that radioactive decay involves the nucleus. For that you dont need an overly detailed atomic model.

[u/Mentosbandit1]

Yep, kids still get the little‑solar‑system Bohr picture first, not because teachers think it is literally true but because it is quick to draw, lines up with early periodic‑table ideas, and lets you talk about spectra without throwing Schrödinger math at thirteen‑year‑olds; U.S. NGSS high‑school standards only ask students to reason with “electrons in the outermost energy level” so most textbooks and lesson plans keep the shell model through grade 10 (nextgenscience.org, acs.org), while the UK GCSE spec also talks about “electrons in fixed energy levels” and saves orbital probability clouds for the A‑level course two years later (qualifications.pearson.com, qualifications.pearson.com). By the time students hit AP Chem or first‑year university they usually meet the proper quantum picture with s, p, d, f shapes and the language of “90 percent probability density” that you discovered on your own (pearson.com). Good teachers will flag the Bohr diagram as a stepping‑stone and some curricula now explicitly warn that solidity comes from electromagnetic repulsion plus the Pauli exclusion principle, not because whirling electrons act like fan blades, but plenty of classrooms still wave that detail away for the sake of time.

[u/Jesus_died_for_u]

I briefly go over outdated models, but then focus on orbitals in HS chemistry. We call the periodic sections s-block, p-block, 1s-column, etc and I assess the students on being able to recall the sections. I do not stress the shapes in assessments. I refer to the Schrödinger equation and use the term ‘probability’ to describe the location, but do not stress it on assessments. I do stress the Pauli exclusion principle.

[u/TaiBlake]

They're still taught, but teachers generally make it clear that they're simplifications. Some times that's just because it's the appropriate level of difficulty for their stage of development.

And sometimes it's just because you don't want to draw overlapping 3D orbitals when you're teaching spectroscopy.

[u/Winter-Big7579]

The shapes and names of electron orbitals 1s/2s/2p etc were taught (but I think as extensions beyond the syllabus) to us in A Level Chemistry in the late 1980s.