What Force Causes Electron Orbitals?

In summary, the electrostatic force keeps the electron bound to the nucleus and the uncertainty principle plays a role in determining its orbit. The electron cannot be treated as a simple object with definite position and momentum, but instead as a probability wave that can exist in a series of states. This allows for a balance between the attractive force of the nucleus and the electron's momentum, allowing it to maintain a stable orbit.
  • #1
hexhunter
100
0
which force separates the electrons and nucleus and causes the electrons to orbit?

a friend told me that the size of the electron means that the nuclei cannot absorb it, but i am still confused and not sure if he knew what i meant in my question.
 
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  • #2
The same reason why the Moon does not fall on Earth: kinetic energy!
 
  • #3
SGT said:
The same reason why the Moon does not fall on Earth: kinetic energy!

That's sort of partly true, but not exactly. Really, the properties that will tell you whether an orbiting object will crash into that which it's orbiting are both the angular momentum and energy. The moon could have the same kinetic energy and distance, but still crash into the Earth if its angular momentum were small. These arguments don't really apply to electrons around nuclei, though, so I don't think it answers the OP's question.

The most straightforward answer to the question is that the electrostatic force keeps the electron bound to the nucleus. Is that what you're looking for, hexhunter?
 
  • #4
i understand that EM stops it from running away, but as the nucleus is +ve and the electron -ve, there is no possibility in my mind that the wouldn't just sink straight into the nucleus, unless if it is just chance that when the nuclei and electrons met, that the electrons where quickly enough forced into the neuclei at their conceivment to make orbit around the nucleus without the EM being too powerful for the electrons to avoid.

though any theory like this would surely suggest that all atoms will neutralise, or do whatever is meant to happen in this event, like a time bomb, not like any of the other 'end of the universe' theories that i have heard of...
 
  • #5
Remember that at the quantum level, there's no friction, gravity, air resitance, etc. to impede it's momentum. Also, it can only reduce it's orbit in discrete steps. In order to move closer to the nucleus, the electron has to spit out a photon to drop into the next energy state (orbital).
 
  • #6
What your friend was probably talking about was that the nulceus is too small to contain an electron from a quantum perspective.

A nucleus is an extremely tiny thing (diameter aprox 10^18cm), and if there was an electron inside it then we would know its location almost exactly. According to the uncertainty principle, the electron would then have a very large (but uncertain) kinetic energy, which would cause it to break out of the nucleus. So electrons reach a compromise, depending on their energy they orbit the nucleus in shells of "surface area" dictated by this rule.
 
  • #7
i understand that EM stops it from running away, but as the nucleus is +ve and the electron -ve, there is no possibility in my mind that the wouldn't just sink straight into the nucleus

here is what you sound like:

"i understand that gravity holds the Earth to the sun, but since gravity is attractive, there is no possibility in my mind that the Earth wouldn't just sink straight into the sun".

Think of swinging a pail above your head. The pail is orbitting you, and you are holding it by a rope. The only force you exert on the pail to make it orbit you, is pulling the rope in towards yourself!
 
  • #8
so the Kinetic energy of the electron is enough to avoid the EM attraction, but keep the orbit, and the electron will never slow, because of the vacuum? but while there is no gravity, there still is the EM from the interaction between the charges.

also, is the orbit round?
 
  • #9
hexhunter said:
also, is the orbit round?

acording, are you talking about the electrons in the s, p, d, or f orbits
The ones in the s orbit are spherical
the p are kinda dumbell shaped
the d are two dumbell crossing at X,Y,or Z axis besides the d5 (5 should be subsized) which is a dumbell with a ring aroud it :confused: (that is what the textbook showed)
the f are for the most part 3 dumbell, but there are some weird ones as well
 
  • #10
locke said:
A nucleus is an extremely tiny thing (diameter aprox 10^18cm), and if there was an electron inside it then we would know its location almost exactly. According to the uncertainty principle, the electron would then have a very large (but uncertain) kinetic energy, which would cause it to break out of the nucleus.

:up:
:approve:
that's it!

however one difficulty in this is that it is sometimes hard to understand how the uncertaincy principle can force an electron to behave in this or that way...
 
  • #11
hexhunter said:
so the Kinetic energy of the electron is enough to avoid the EM attraction, but keep the orbit, and the electron will never slow, because of the vacuum? but while there is no gravity, there still is the EM from the interaction between the charges.

Alright, there seem to be two points of confusion here, one classical and one quantum. If we could treat atoms as mini solar systems then Crosson's explanation would end the story. That is, the electron would be pulled inwards by the attraction of the proton, but by Newton's first law, its momentum would want to keep carrying it in some other direction. Some balance would be achieved between these two effects that would allow the electron to continue in an orbit around the nucleus, just as happens with the planets around the sun.

However, this is not a good description of atoms. It turns out that, at these scales, the laws of quantum mechanics begin to become apparent and the electron begins to behave in ways that make no sense in the description I gave above. For this, locke gave a good answer. The electron cannot be treated as a simple object with definite position and momentum, but instead as a sort of probability wave that can exist in a series of states. These were partially described by lawtonfogle.
 
  • #12
SpaceTiger said:
For this, locke gave a good answer. The electron cannot be treated as a simple object with definite position and momentum, but instead as a sort of probability wave that can exist in a series of states.
Yeah. I learned to consider the area around the nucleus as an electron orbital cloud. A haze of varying probabilities, and somewhere in that cloud the probability of an electron being there is high enough that it really is.
 
  • #13
Danger said:
A haze of varying probabilities, and somewhere in that cloud the probability of an electron being there is high enough that it really is.

Keep in mind that the "cloud" and the probability distribution function are one and the same. Your description is a sort of semi-classical way of thinking about it, but I think the Copenhagen interpretation implies that the probability "cloud" is the most fundamental physical reality.
 
  • #14
SpaceTiger said:
Keep in mind that the "cloud" and the probability distribution function are one and the same. Your description is a sort of semi-classical way of thinking about it, but I think the Copenhagen interpretation implies that the probability "cloud" is the most fundamental physical reality.
Yeah, that's what I meant. Bad choice of phrasing on my part. I'm used to dealing with people who have no knowledge of science whatsoever, so I sometimes translate sloppily.
 
  • #15


SpaceTiger said:
the Copenhagen interpretation implies that the probability "cloud" is the most fundamental physical reality.

Correct me if I sound dumb, but the 'most fundamental physical reality' is uncertainty?
 

1. What is the force that causes electrons to orbit the nucleus?

The force that causes electrons to orbit the nucleus is called the electromagnetic force. This force is responsible for the attraction between positively charged protons in the nucleus and negatively charged electrons.

2. How does the electromagnetic force keep electrons in orbit?

The electromagnetic force acts as a centripetal force, pulling the electron towards the nucleus and keeping it in orbit. This force is balanced by the electron's inertia, creating a stable orbit.

3. Are there other forces involved in electron orbitals?

Yes, in addition to the electromagnetic force, there is also the weak nuclear force and the strong nuclear force. These forces play a role in determining the stability and arrangement of electrons in an atom.

4. How do electron orbitals differ from the orbits of planets around the sun?

The orbitals of electrons are different from the orbits of planets around the sun because they are not fixed paths. Instead, they are regions of probability where an electron is likely to be found. Additionally, the electromagnetic force governs the motion of electrons, while gravity governs the motion of planets.

5. Can the force that causes electron orbitals be seen or measured?

The electromagnetic force cannot be seen, but it can be measured through experiments such as electron diffraction or spectroscopy. These experiments provide evidence for the existence and behavior of the force that causes electron orbitals.

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