Why do people think that electrons in atoms are tiny beads flying in circles around the nucleus?

[Jim]

What people tell us or what a deity tells us?

What people tell us.

 

[Jim]

I blame this guy...

My forum gods are the best, and who would deny that they exist?

 

[Jim]

But there are two separate things here:

i) the way we may take on trust the evidenced-based* ideas of science, without demanding to see that evidence with our own eyes, and

ii) the way we may take certain other ideas on trust, which are not evidence-based in the same way at all.

What we have been talking about up to now is (i). But if someone is questioning the basis of religious belief they are almost certainly talking about (ii).

Do not try to establish a false equivalence by conflating the two.

* evidence in the scientific sense has to meet certain criteria, viz. observations of nature, that can be reproduced by different people, in a variety of ways.

But there are two separate things here:

i) the way we may take on trust the evidenced-based* ideas of science, without demanding to see that evidence with our own eyes, and

ii) the way we may take certain other ideas on trust, which are not evidence-based in the same way at all.

What we have been talking about up to now is (i). But if someone is questioning the basis of religious belief they are almost certainly talking about (ii).

Do not try to establish a false equivalence by conflating the two.

That isn’t where I was going. For now it was just to see what people think about trusting what other people say. Everything you’ve said has been very helpful for that purpose, and some others too, and I learned a valuable new lesson from it.

 

[Jim]

At what stage in your school career did you give up physical science (physics and chemistry)? If you stopped by the age of 16 it is not very surprising.

I never gave them up, I majored in electrical engineering at Purdue University, and a few years ago I had to train myself in organic chemistry, to check the English translations of research reports on industrial water purification.

 

[DanishCrow]

Because the nucleus surrounded by little "planetary rings' of electrons is still a commonly used symbol for atoms in many places. I think schools are just now converting to the "electron cloud" model, which is a bit more accessible.

 

[exchemist]

I never gave them up, I majored in electrical engineering at Purdue University, and a few years ago I had to train myself in organic chemistry, to check the English translations of research reports on industrial water purification.

Ah well with engineering I've found people can skip a great deal of physical science. I was taught physics in the 1st year 6th form by an engineer who did not believe in molecules! (He was a good teacher in fact.) I would have thought, though, that you might have had to learn a bit of quantum theory in order to master electronics: metallic bonding, valence band vs. conduction band, photodiodes etc.

And yet you got by with the Rutherford-Bohr model of the atom, you say. Well, that just goes to show how useful a model it can be, even if to a chemist or physicist it is obvious that it won't do.

 

[Jim]

Because that was the old Rutherford -Bohr model of the atom, developed before quantum theory, which is still taught at elementary level in schools. It is easier to grasp, for people who are not going to learn physical science to an advanced level, than the more modern model involving wave-particle entities.

Probably because it's a popular schematic.

Because for most people's purposes, it's a perfectly adequate description

It's only a model. In reality, the protons and neutrons are particles but the electrons form sort of a "cloud" that's basically barely visible. They do, however, behave as particles thus the way we model them is for our own convenience.

Do you see anything wrong with teachers not telling their students that it’s only an analogy, and letting them think that the electrons in atoms really are tiny beads flying in circles around the nucleus?

 

[Kangaroo Feathers]

Do you see anything wrong with teachers not telling their students that it’s only an analogy, and letting them think that the electrons in atoms really are tiny beads flying in circles around the nucleus?

Welcome to explaining anything to anyone. Pratchett calls this "lies to children". If you explain anything complex, you have to start with inaccurate simplistic approximations, and build up to the complex. This is the case with teaching anyone anything.

 

[exchemist]

Do you see anything wrong with teachers not telling their students that it’s only an analogy, and letting them think that the electrons in atoms really are tiny beads flying in circles around the nucleus?

It's not just an analogy. The evidence is that the electrons are in motion about the nucleus. They are just not simply point particles, going round in predictable Newtonian "orbits".

So I don't really see anything wrong with the Rutherford-Bohr model being presented, though for older students I would think a good teacher would indicate that this is a simplified model and there is a lot more to be learnt about it later for those that go on to more advanced study.

In teaching there is always a balance to be struck between getting the basic information across without confusing the student, and giving a more complete picture. I think it is tacitly understood by all students that they initially learn a simplified version of the subject, in history or languages just as much as in science.

Where I do suspect some science teaching is lax is in not explaining that science deals in models of reality, of varying degrees of approximation. The issue as always is where one puts this, which is really a sidebar on the philosophy of science, in a crammed curriculum.

I was lucky in that my chemistry teacher made a point of explaining that everything we learnt was a model. But then in chemistry this is particularly apparent. We often have more than one model for the same thing, depending on what we are trying to do. The complexity of chemistry (so many elements, all with different numbers of electrons, in different subshells, combining to make polyatomic molecules) makes approximation and simplification essential. So you need to keep your head and be able to recognise that at some level all these models are aspects of what is "really" going on.

A bit like the doctrine of the Trinity I suppose.........

 

[Jim]

Ah well with engineering I've found people can skip a great deal of physical science. I was taught physics in the 1st year 6th form by an engineer who did not believe in molecules! (He was a good teacher in fact.) I would have thought, though, that you might have had to learn a bit of quantum theory in order to master electronics: metallic bonding, valence band vs. conduction band, photodiodes etc.

And yet you got by with the Rutherford-Bohr model of the atom, you say. Well, that just goes to show how useful a model it can be, even if to a chemist or physicist it is obvious that it won't do.

We might have learned some quantum physics. I remember learning about Schrödinger’s equation. I don’t remember what year it was. We learned about electrical properties of diodes and transistors, but not the physics.

 

[Jim]

Welcome to explaining anything to anyone. Pratchett calls this "lies to children". If you explain anything complex, you have to start with inaccurate simplistic approximations, and build up to the complex. This is the case with teaching anyone anything.

Is that to say that you don’t see anything wrong with it?

 

[exchemist]

We might have learned some quantum physics. I remember learning about Schrödinger’s equation. I don’t remember what year it was. We learned about electrical properties of diodes and transistors, but not the physics.

If you learnt about Schrödinger's equation you must have covered wave-particle duality and atomic orbitals. But perhaps as an engineer you would not have used the orbital idea enough for it to stick.

For a chemist it is different: we have to know what electrons are in s orbital and what are in p or d orbitals, because it is the overlap (and phase) of these that determine chemical bonding. Also we need to understand spectroscopy, as it is one of the most powerful analytical tools in the chemist's armoury.

 

[Mindmaster]

Warning, Heisenberg uncertainty principle imminent!

It applies to many things, BTW, not even just atoms but fundamental forces like gravity. (We still have no idea what gravity "is" just how it reacts on things.)

 

[Shad]

Some people think that the electrons in atoms are tiny little beads flying in circles around the nucleus. Why do some people think that?

School text books in my view. Often pictures are used a part of an explanation. People will reference the pictures rather than the text.

 

[Mindmaster]

Do you see anything wrong with teachers not telling their students that it’s only an analogy, and letting them think that the electrons in atoms really are tiny beads flying in circles around the nucleus?

No, because at that level of understanding it's more important what they are doing rather than what they are. We know much more about how they interact and that is generally the focus of grade school education. For that purpose, a simple model using a "virtual electron" is more sensible -- even though there isn't really an "electron" as a particle -- it functions more like a cloud, or a wave... To accurately model the electron first you'd have to explain that it's really not attached to the atom (electrons sort of "swarm or rest on them", they also are freely reclaimed to the atom from other sources of them), then you'd get into a complicated discussion of radio or cellular communication because that'd be the only visible approach. Sometimes, the simplification is a useful tool -- especially in this one, since you'd have to go so far off-topic to explain the one little thing.

 

[Kangaroo Feathers]

Is that to say that you don’t see anything wrong with it?

That's to say I understand it is a necessary step in teaching. Be my guest and try explaining the quantum electron cloud model to a complete novice. Think of ANY complex system. To explain it to someone you start out with simple, inaccurate approximations, and improve accuracy as the learner increases knowledge. There's nothing "wrong" with it, it's how people learn, it's how people have always learned. I promise you, any complex system you are not a noted expert in, your understanding will have similar false, useful approximations.

I see you think that you're making some devastatingly insightful point, but it's not coming across. What are you trying to say?

 

[exchemist]

No, because at that level of understanding it's more important what they are doing rather than what they are. We know much more about how they interact and that is generally the focus of grade school education. For that purpose, a simple model using a "virtual electron" is more sensible -- even though there isn't really an "electron" as a particle -- it functions more like a cloud, or a wave... To accurately model the electron first you'd have to explain that it's really not attached to the atom (electrons sort of "swarm or rest on them", they also are freely reclaimed to the atom from other sources of them), then you'd get into a complicated discussion of radio or cellular communication because that'd be the only visible approach. Sometimes, the simplification is a useful tool -- especially in this one, since you'd have to go so far off-topic to explain the one little thing.

Er well, if not exactly attached, it is at least held captive, by electrostatic attraction from the nucleus.

The electron can't fly away unless you jack up its combined kinetic and potential energy enough that it can reach "escape velocity" from the nucleus, by giving it what we call the "ionisation energy", so that it escapes and what is left is an ion with a +ve charge.

 

[Nakosis]

Some people think that the electrons in atoms are tiny little beads flying in circles around the nucleus. Why do some people think that?

That's what I was taught in school. Later I learned it is about forces. Probably not as easy to wrap one's head around.

 

[Jim]

That's to say I understand it is a necessary step in teaching. Be my guest and try explaining the quantum electron cloud model to a complete novice. Think of ANY complex system. To explain it to someone you start out with simple, inaccurate approximations, and improve accuracy as the learner increases knowledge. There's nothing "wrong" with it, it's how people learn, it's how people have always learned. I promise you, any complex system you are not a noted expert in, your understanding will have similar false, useful approximations.

I see you think that you're making some devastatingly insightful point, but it's not coming across. What are you trying to say?

I’m not trying to say anything. I’m trying to find out what people think about something. When a teacher presents the planetary model, they could say “this is just an analogy, and not an actual physical description.” Instead sometimes teachers let their students think that it’s an actual physical description, even if they don’t believe that, themselves. Do you see anything wrong with that?

 

[Mindmaster]

Er well, if not exactly attached, it is at least held captive, by electrostatic attraction from the nucleus.

The electron can't fly away unless you jack up its combined kinetic and potential energy enough that it can reach "escape velocity" from the nucleus, by giving it what we call the "ionisation energy", so that it escapes and what is left is an ion with a +ve charge.

Well, like I said, it's definitely sort of OT in the context of what the school is trying to teach.

Most schools are teaching about atoms and the periodic table at the same time, but this other stuff would inject a whole lot of "exceptions" rather than teach any base rules. The short of it is, I think that's why it's avoided, not because it cannot be taught.