# Atomic Model

#### Donn P

Lets say that you took a Hydrogen Atom and expanded it to the size of lets say a basketball. Im not just saying the atom itself but the nucleus. If the nucleus expanded to the size of a basketball; how would the electron size up porportionally. Now keeping it all porportional what would the effects be? What would be the angular velocity of the electron be? I mean how far would the electron be away from the protron? What would be the static charges be and how large would those paticluar potentials(voltage) be? How dense would the atomic particles be? Would they weigh something? Would it have a color? Would it have a sound like a loud humming or something? Im just trying to get a visual of how an atom or hydrogen atom would be. By getting it out of the micro/nanometer world it would just be easier for me. I want this "basketball model" to keep the same characteristics that would be found in the nanometer world like increased surface area and etc. If anyone has a link or something that would be helpful or if you need to alter the "basketball model" to a large body like a "planet model" then please do so.

Personally I think that we need to visualize what is happening in atomic physics. We already have lots and lots of equations, theories, and arguments that go with that. For example, Einstein. I read a couple books about him and he developed his theory of realitivity by actually day-dreaming of running next light. I just think that we need to use our senses to get a "feel" of whats happening at the atomic level. Or maybe this is just me.......

Related Atomic and Condensed Matter News on Phys.org

#### neu

You're barking up the wrong tree.

The equations describe what goes on much better than any qualitative explanation. Especialy when considering atomic scale interactions, as they are governed by quantum mechanics and are not at all analogeous to a humming basketball

understanding the maths is the best you can get. Visualisation can only help with this, not replace it.

You might think this overly pendantic but it the exact reason why QM is used

#### Repetit

Like Neu said, the world of atoms and molecules is governed by quantum mechanics, and quantum mechanics is so much different from macroscopic quantities like basketballs. It is impossible to draw an analogy between the two.

In school atoms are sometimes visualized as planets (the nucleus) with orbiting moons (electrons). This is maybe okay for a very basic understanding of the concept, but it gives a totally wrong picture of reality. Trying to project quantum mechanics onto everyday phenomena only gives rise to a wrong understanding of QM.

#### JPRitchie

Donn P:
The rest mass of the proton is 1836 times larger than that of the electron. This large difference is the basis some important equations, such as the Born-Oppenheimer equation. So having a qualitative knowledge of the realtive sizes of things can result in quantitative advances. Also, regarding pictures, just about every book on quantum mechanics and most first year college chemistry texts have multitudes of illustrations of hydrogen atom orbitals. I'll leave the leg work to you.
-Jim

#### neu

The lengendre equations were first used in relation to planetary motion, and many other aspects of QM originaly derived from clasical theories, but you've got to break the link somewhere.

#### Donn P

What I am getting at neu, is why do we have to "break the link somewhere", I mean why can't we try to make that connection instead of leaving QM as its own idea and theory. My personal belief is that the forces that constantly surround our life wether it be on a micro or macro scale are connected (sorta like string theory). Atomic physics in my eyes is a slow growing study. The basics of QM was laid out almost a 80 years ago and what does our generation have to show for? Maybe we need to approach QM with a different ideal. Why not try to make a connection between things that people already understand and things that people have no idea about?

#### ZapperZ

Staff Emeritus
2018 Award
What I am getting at neu, is why do we have to "break the link somewhere", I mean why can't we try to make that connection instead of leaving QM as its own idea and theory. My personal belief is that the forces that constantly surround our life wether it be on a micro or macro scale are connected (sorta like string theory). Atomic physics in my eyes is a slow growing study. The basics of QM was laid out almost a 80 years ago and what does our generation have to show for? Maybe we need to approach QM with a different ideal. Why not try to make a connection between things that people already understand and things that people have no idea about?
At the risk of repeating myself, I'll point out to you what this has been asked many times that I've a ready-made reply for it http://physicsandphysicists.blogspot.com/2006/09/why-is-quantum-mechanics-so-difficult.html" [Broken].

Zz.

Last edited by a moderator:

#### Donn P

Its hard for me to believe that QM is just going to continue as a science that is purely based on equations. I understand that mathematics is the medium to QM but do you all agree that it is going to that way? Will there ever be a point where QM is as understandable and can be modeled to a science like electronics for example? ZZ I know that there is no starting point to connect QM with other popular ideas and theories but has anyone tried? The fact that mechanics is in this popular term implies that there is a mechanical funtion to this study. It is just that as soon as you want to study QM your hit with equations and your thrown on a one-way street. Free-thinking has always spawned new and ground-breaking ideas and theories.

#### JPRitchie

Donn P,
There are so many examples of the kind of thing that you seek that it is hard to know where to start. But, here are my top 3.
1. Computational chemistry - The 1998 Nobel Prize in Chemistry was awarded, in part, to John Pople. He was a principal behind the Gaussian programs. These programs, and the quantum mechanics in them, have provided real-life applications from biology to electronics. This is one of the things Pople's generation has to show for QM.
2. Woodward-Hoffman rules - These scientists discovered some qualitative rules governing chemical reactions and can determine whether certain types of reactions are "allowed" or "forbidden". Other approaches developed independently by M.J.S. Dewar and H.E. Zimmerman showed that aromaticity, the same QM effect that stabilizes benzene, determines whether certain reactions are allowed or forbidden. Orbital topology and all of topology, incidentally, are the quantitative study of shapes, surfaces, etc. and 3-d objects.
3. Atoms in Molecules - This name summarizes an approach developed by Richard F.W. Bader. Using the principal of stationary action, he shows how one can draw pictures of bonds in molecules. These pictures aren't qualitative, but rather show the solution to a set of equations that, otherwise, would be difficult to get the same insight from.
Search on any of the names mentioned above and you'll find some starting points for serious and visually stimulating study.
-Jim

#### Donn P

I have no experience in physics just to let you all know. I have learned what I know from the one website Wikipedia, which seems to be the link everyone uses to direct some questions on these forums. Im not here to argue with anyone because you all would blow me out of the water with knowlege. My starting point is the Hydrogen Atom. One electron, one protron, and one neutron. Then I move one to the next atom Helium. Just trying to understand things on my own with very little direction. But thanks to everybody who replied. BTW, experimentally, how can you isolate just one atom? If possible I mean.

#### ZapperZ

Staff Emeritus
2018 Award
Its hard for me to believe that QM is just going to continue as a science that is purely based on equations. I understand that mathematics is the medium to QM but do you all agree that it is going to that way? Will there ever be a point where QM is as understandable and can be modeled to a science like electronics for example? ZZ I know that there is no starting point to connect QM with other popular ideas and theories but has anyone tried? The fact that mechanics is in this popular term implies that there is a mechanical funtion to this study. It is just that as soon as you want to study QM your hit with equations and your thrown on a one-way street. Free-thinking has always spawned new and ground-breaking ideas and theories.
You should also consider that "free thinking" based on ignorance has also spawned a lot of garbage that went nowhere. Just look at all those crackpot websites.

Zz.

#### Dick

Homework Helper
There is a wealth of layman level literature on such subjects entitled something like the "World of Walter Mitty" by Gamow. Like 'what would the world look like if the speed of light were 10 m/sec' and 'what if Planck's constant were 1 kg*m^2/sec'. Pretty entertaining too.

### Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving