What holds conducting electrons from flying off into vacuum

In summary: Valence band behaves differently compared to the Conduction band. In summary, the conducting electrons in a conductor suspended in an external electric field are still bound to the metal due to the periodic potential of the ions. This is why we have the "work function". However, with a strong enough electric field, these electrons can be sent off, as seen in electronic vacuum tubes like TV picture tubes. The Valence band and the Conduction band behave differently in this case. For more information, you can refer to the articles on Electrical Conduction, Valence band, and Electron Binding Energy.
  • #1
bob900
40
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In a conductor suspended in an external electric field, in a vacuum, what holds the conducting electrons inside the conductor? Why don't they just fly off into space, under the influence of the field? If they are free enough to move between the atoms of the conductor, this means the force from the atomic nuclei etc. is not great enough to bind them to a specific location/atom. So why is it any different at the surface?
 
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  • #3
bob900 said:
In a conductor suspended in an external electric field, in a vacuum, what holds the conducting electrons inside the conductor? Why don't they just fly off into space, under the influence of the field? If they are free enough to move between the atoms of the conductor, this means the force from the atomic nuclei etc. is not great enough to bind them to a specific location/atom. So why is it any different at the surface?

While in the simplest approximation these electrons are considered to be "free electrons", in reality, they aren't! They still see the periodic potential of the ions of the metal. So in essence, they are still bounded to the metal. This is why we have the "work function".

Zz.
 
  • #4
Naty1 said:
....
Try here too:

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

With a strong enough electric field, you can send electrons off...

If you want more detail, try ELECTRON BINDING ENERGY


Yes as in any sort of electronic vacuum tube. say a TV picture tube

Dave
 
  • #5


The reason conducting electrons do not fly off into space in a vacuum is due to the presence of an electric field. In a conductor, the electrons are free to move between the atoms of the material, but they are still affected by the external electric field. This field exerts a force on the electrons, causing them to move within the conductor. However, the electrons are also bound by the positive charges of the atomic nuclei within the conductor. This creates a balance between the external electric field and the attractive force from the nuclei, keeping the electrons confined within the conductor.

At the surface of the conductor, the same balance of forces applies. While the electrons are still free to move within the material, the attractive force from the nuclei is still present. This prevents the electrons from flying off into space, even under the influence of the external electric field.

It is important to note that the strength of the attractive force from the atomic nuclei depends on the material and its properties. In some materials, the force may be strong enough to keep the electrons tightly bound, while in others, the electrons may be more loosely bound and able to move more freely. However, in all cases, the presence of an external electric field will still affect the movement of the electrons within the material.

In summary, the balance of forces between the external electric field and the attractive force of the atomic nuclei is what holds conducting electrons within a conductor in a vacuum. This allows for the flow of electricity and the properties of conductivity in materials.
 

Related to What holds conducting electrons from flying off into vacuum

1. What is the force that holds conducting electrons from flying off into vacuum?

The force responsible for holding conducting electrons from flying off into vacuum is known as the electrostatic force. This force is caused by the attraction between the negatively charged electrons and the positively charged nuclei of the atoms in the conductor.

2. How does the structure of a conductor prevent electrons from flying off into vacuum?

Conductors are made up of atoms with a large number of free electrons in their outermost energy level. These electrons are able to move freely within the conductor, but are still held in place by the electrostatic force between the electrons and the nuclei. This structure allows the electrons to remain within the conductor and prevents them from flying off into vacuum.

3. What role do valence electrons play in preventing conducting electrons from flying off into vacuum?

Valence electrons are the outermost electrons in an atom that participate in chemical bonding. In conductors, these electrons are able to move freely, contributing to the flow of electricity. However, they are still held in place by the electrostatic force between the electrons and the nuclei, preventing them from escaping into vacuum.

4. Can conducting electrons ever escape into vacuum?

Under certain conditions, conducting electrons can escape into vacuum. This is known as electron emission and is commonly observed in vacuum tubes and electron microscopes. However, in most cases, the electrostatic force in conductors is strong enough to hold the electrons in place.

5. How does the temperature of a conductor affect the ability of electrons to remain within the conductor?

The temperature of a conductor can affect the movement of electrons within the material. At higher temperatures, the atoms in the conductor vibrate more vigorously, making it more difficult for the electrostatic force to hold the electrons in place. This can result in some electrons gaining enough energy to escape into vacuum, causing the conductor to lose its conductivity.

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