# Limit to generating static electricity via contact?

• atommo
In summary, a thunderstorm can't really run out of lightning due to outer space radiation, but if the particles become positively charged and their only contacts were the material stripping their electrons and filtered air, they would eventually lose all their electrons.
atommo
Let's say you are rubbing a balloon on your hair to make it charged. If you then discharge the balloon and rub it on your hair again (and repeat this process numerous times). Would your hair run out of electrons so eventually you would be unable to charge the balloon, or would your hair gain electrons from elsewhere before this point?

I was reading up on how thunderstorms make lightning and that the particles collide/separate out with different charges (top of the cloud becomes positive, bottom of cloud is negative). In this way, if all the lightning of a thunder cloud strikes the ground (and not the top of the cloud where all the positive particles are) [this is purely theoretical as it is highly unlikely that would actually happen] then the top remains positively charged. Would this in theory mean a thunder cloud could 'run out' of lightning (as the bottom particles couldn't gain more electrons)?

Sidenote: My understanding of thunderstorms is that ice particles become negatively charge while water particles become positively charged. They collide with each other because of the extreme winds in a storm cloud. The lighter water particles get blown upward by updrafts while the ice is heavier so stays lower down. This is how the negative/positive separation occurs. (Reference: How does lightning form?)

Dale
atommo said:
Summary: Can you run out of electrons when continuously rubbing two materials together (and discharging one) to create static charge?

I was reading up on how thunderstorms make lightning and that the particles collide/separate out with different charges (top of the cloud becomes positive, bottom of cloud is negative). In this way, if all the lightning of a thunder cloud strikes the ground (and not the top of the cloud where all the positive particles are) [this is purely theoretical as it is highly unlikely that would actually happen] then the top remains positively charged. Would this in theory mean a thunder cloud could 'run out' of lightning (as the bottom particles couldn't gain more electrons)?

There is an almost continuous incoming of charge into the Earth's atmosphere, mainly from outer space

you may also find this of interest ...

http://www.feynmanlectures.caltech.edu/II_09.html

berkeman and atommo
Interesting. So thunderstorms can't really run out due to outer space radiation.

However, what about the example of a balloon and hair/fabric? Since that would be on the surface, I'm guessing there aren't so many free electrons available to 'recharge' the material losing electrons.

Since I haven't heard anything else I asked around elsewhere:

Q: if particles (lets say dust particles) became positively charged and their only contacts were the material stripping their electrons and filtered air, would they completely lose their electrons and not be able to charge the material they're contacting (such as silicon) after a certain amount of time?

A: yes, or at least, they have reached charge equilibrium with their environment, and will not be able to supply electrons until it acquires them from some other source in the environment that is out of equilibrium.

Which is what I expected.

I was curious about this since devices like the Wimhurst Machine don't actually lose electrons to the earth- they flow around in a circuit (so while material does lose electrons, it gains those same electrons back later after the static discharge)

## 1. How can static electricity be generated through contact?

Static electricity can be generated through contact by rubbing two materials together, causing a transfer of electrons between the two surfaces. This creates a build-up of static charge on the surfaces, which can then be discharged through contact with a conductor.

## 2. What materials are best for generating static electricity through contact?

Materials that have different levels of electron affinity, or the ability to gain or lose electrons easily, are best for generating static electricity through contact. Examples include rubber and fur, or plastic and wool.

## 3. Can static electricity be generated through contact with non-conductive materials?

Yes, static electricity can still be generated through contact with non-conductive materials. While non-conductive materials cannot conduct electricity, they can still transfer electrons through friction, resulting in a build-up of static charge.

## 4. Is there a limit to how much static electricity can be generated via contact?

Yes, there is a limit to how much static electricity can be generated via contact. This limit is based on the size and surface area of the materials being rubbed together, as well as the humidity and temperature of the surrounding environment.

## 5. How can the amount of static electricity generated through contact be controlled?

The amount of static electricity generated through contact can be controlled by adjusting the materials being rubbed together, the speed and pressure of the rubbing motion, and the environmental conditions. For example, increasing the humidity in the room can decrease the amount of static electricity generated.

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