# What force classically held electron in the orbit?

• oldspice1212
In summary, the classical electromagnetic force holds an electron in an atom in an orbit. Quantum mechanics is required to understand why this is the case.

#### oldspice1212

Hey, what force classically held electron in the orbit? Also what force is it actually (quantum mechanics).

I think it was the electromagnetic force classically, I haven't been able to find a legit source that says it was directly that, but when I do calculations with electrons and atoms I'm often using the electric potential. And for quantum mechanics, I'm not really sure at all, just curious and want to know, if someone has some sources?

Strictly speaking, there is no proper classical description of this system. But the only force you could actually think of classically is electromagnetic force, otherwise gravitational force is too weak and weak, strong interactions are purely quantum mechanical gauge theories that have no classical counterpart. However, the classical electromagnetism would cause problems due to radiative electrodynamics.

Quantum mechanically, we do not speak of forces in microscopic regime; we talk about potentials (or gauge particles in quantum fields). The electrons have bounded wavefunctions if the potential is larger than the total energy. For orbital electrons, the main contribution is electromagnetic potential. Again the gravity is too weak and length scale is too large for the nuclear interactions.

• oldspice1212
If you look up the Bohr Model (this link and many others) you will see an early Classical model, based on an actual charged particle in orbit around a nucleus - with the same equation as you will get for any non quantum system involving real forces. It doesn't work properly, though, because there are only certain, quantised energy levels ('orbit radii') that are found with atoms. The Shroedinger wave equation was the next step and that does a much better descriptive job.

• oldspice1212
Depends on what you mean by "holds in orbit."

If you mean, what interactions does an electron in an atom have? Then the answer is electromagnetism is extremely close to the entire story. You can understand experiments exceedingly accurately using only E&M. And a finite sized nucleus, which arises from nuclear forces.

If you mean, why does the electron not drop out of orbit and cozy up to the positive charge in the proton, that's a different matter. It's not exactly an interaction. It's more to do with the fact that various quantum numbers that are conserved could not be conserved if that happened. It's more a lack of interaction that would be required for such a thing to move forward.

• oldspice1212
Thank you everyone, you have answered my question.
I appreciate it!

## 1. What is the force that holds electrons in orbit?

The force that holds electrons in orbit is the electromagnetic force. This force is responsible for keeping the negatively charged electrons in orbit around the positively charged nucleus of an atom.

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

The electromagnetic force works by attracting opposite charges and repelling like charges. In the case of an atom, the positively charged nucleus attracts the negatively charged electrons, creating a stable orbit.

## 3. Is the electromagnetic force the only force that holds electrons in orbit?

Yes, the electromagnetic force is the only force responsible for holding electrons in orbit. It is the strongest force in an atom and is much stronger than the force of gravity.

## 4. How does the strength of the electromagnetic force affect the orbit of electrons?

The strength of the electromagnetic force determines the stability of an electron's orbit. The stronger the force, the more stable the orbit will be. This is why electrons in the innermost energy levels of an atom have a stronger binding to the nucleus than those in outer energy levels.

## 5. Can the electromagnetic force be overcome to remove electrons from their orbit?

Yes, the electromagnetic force can be overcome through the input of energy. This can be achieved through processes such as heating, ionization, or excitation, which can cause electrons to move to higher energy levels or leave the atom altogether.