Other Atomic Models?

The planetary theory of electrons orbiting a nucleus of neutrons and protons is not the modern theory. The present accepted theory is referred to as 'the electron orbital theory." In this theory the only molecular atom that anywhere behaves as a planetary model is monatomic hydrogen.

An early model was called the plum pudding molecule, which viewed an atom as an electron pudding with neutrons and protons as plums in the pudding. Compton's (I believe) experiments with shooting atoms of an inert gas (helium?) with high speed neutrons laid this theory to rest, because an atom had to have a massive nucleus surrounded by a field of electrons.

Rap

Actually it was Rutherford with the gold foil in the Conservatory. He discovered that atoms are mostly empty space. This was deduced from the fat that particles fired at the foil almost always went straight through without deflection.

Here is a new *ahem* theory of the atom:
http://en.wikipedia.org/wiki/Randell_Mills

/Kayyam

The modern theory is that the electrons surround the nucleus in a cloud, and the cloud is not necessarily spherical, but takes on various different shapes for different atoms.

Actually, it's a cloud of probability, but that's a story for another day.

Quantum atomic theory still viable then?

What about atomic theory as a function frequency/oscillation?

Do you mean pulsing Chum?

The wave functions (simplest cast-- f''(x)+nf(x)=0) are consistent with quantum theory. The wave function solution frequencies are quantum multiples (f=2npi) where n is an integer.

Rap

Would you be able to define "simplest cast"?

pardon--two errors first missed the word and second a slight clarification

that should be "simplest case"

& f''(x)+n^2f(x)=0 is a differential equation, meaning that the second derivative of a function plus n^2 times that function is zero. The solution is a sine curve, a pulsating curve that starts at zero and repeats itself at a regular frequency (2npi). n is restricted to integers (e.g. quantum) and is consistent with the wave format of electromagnetism (light, particle mechanics, and electricity).

What is interesting is that quantum mechanics is always applicable--even in baseball--it is just that in baseball the mass is so great that the particle sinusoidal motion is so miniscule that it is not noticeable and baseball is best modeled classically. That is why Willie Mays is considered one of the greatest classical experimental physicists of all times.

Rap

Interesting and funny!

Re: Other Atomic Models?

I prefer the electron "Cloud" model.

Re: Other Atomic Models?


It works well on the microscopic scale as electron orbital theory and the Hoffman rules, but when analyzing the ballistics of baseball the electron cloud model is overkill.

Rap

Re: Other Atomic Models?

I think that one went over my head.

Quantum mechanics is not only "viable" but it one of the most well supported physical theories we have. And by support, I mean that it makes myriad verifiable predictions. There is no other theory in the same league. It has lead to many useful inventions including those of the semiconductor revolution.

/Kayyam

To any and all:

please illuminate the application of Quantum Mechanics to both the development and the underlying theory of operation as per:

1) the PNP / NPN silicon transistor

2) the silicon diode

and

3) electron flow in a conductor


Thanks muchly!

ha ha! That is for another thread.

/Kayyam

Being it's my thread.......

http://www.ecse.rpi.edu/~schubert/Course-ECSE-6968%20Quantum%20mechanics/Ch00%20Prelims.pdf

http://en.wikipedia.org/wiki/Semiconductors

http://en.wikipedia.org/wiki/Quantum_physics

Amplification of input appreciated (pun)!

Hmm, well I didn't think you were serious. All three topics are related to the idea of electron conductivity, or band gap. The band gap is the amount of energy required to knock an electron loose. Thus for metals the band gap is small, for insulators it is large and for semiconductors it is somewhere in between. The band gap is a direct consequence of atomic and molecular orbital theory and can be calculated through solution of the Shroedinger equation.

Diodes and transistors are usually silicon based circuit elements which take advantage of the variable conductivity of semiconductors. This is accomplished by doping the semiconductor crystal with impurities.

/Kayyam

If I had to look somewhere to say matter, energy and space time (and they are related) aren't what we model them to be - I would look for surprises in the geometry of space time - google "scale relativity" and the "fractal universe"

Kind thanks!