What Must Conductors be Made of

  • I
  • Thread starter FS98
  • Start date
  • Tags
    Conductors
In summary, conductors in the abstract sense require charge carriers, which are usually in the form of mobile electrons in solids, but can also include positive ions in liquids and gases. In order for a conductor to work, there must be both positive and negative charges present. However, in some cases, beams of charged particles can conduct over short distances but require guiding and refocusing to prevent spreading due to mutual repulsion. The concept of conductors existed before a solid understanding of what they are made of, and while the strong nuclear force can hold particles together, it is not practical for use in conductors.
  • #1
105
4
When we think of conductors in an abstract sense, charges can flow freely through them.

What are these abstract conductors made of?

I understand that conductors in the real world are made primarily of protons and electrons, But that it doesn’t seem like that is necesarrily the case. If we had particles with different masses and charges, I suspect that we could have a conductor made from those instead of protons, electrons and neutrons.

So what must a conductor in the abstract sense be made of? Must there be both positive and negative charges? Are there other requirements?

I believe electricity was discovered before the electron. Was the idea of conductors around before we had a solid understanding of what they are made of?
 
Physics news on Phys.org
  • #2
A conductor needs charge carriers. These are usually in the form of mobile electrons only, because, in solids, the positive charges are locked in place. In liquids and gases (plasma), the positive ions can also move and contribute to the conduction process.
 
  • Like
Likes FS98
  • #3
sophiecentaur said:
A conductor needs charge carriers. These are usually in the form of mobile electrons only, because, in solids, the positive charges are locked in place. In liquids and gases (plasma), the positive ions can also move and contribute to the conduction process.
Does their need to be both positive and negative charge carriers? Or could you theoretically have a conductor with only one or the other?
 
  • #4
FS98 said:
Does their need to be both positive and negative charge carriers? Or could you theoretically have a conductor with only one or the other?
In solids, the positive charges cannot move. Metals are excellent conductors, due to the highly mobile valence electrons. There are, of course, equal numbers of negative and positive charges in a wire.
 
  • Like
Likes FS98
  • #5
FS98 said:
Does their need to be both positive and negative charge carriers? Or could you theoretically have a conductor with only one or the other?
If a conductor had only negative charges and no positive charges, what would keep the negative charges inside the conductor, against their mutual repulsion?

We actually do produce beams of charged particles at accelerators, but we use magnetic fields to keep the beams focused. And the beams travel through vacuum, not through a conductor.
 
  • Like
Likes FS98
  • #6
jtbell said:
If a conductor had only negative charges and no positive charges, what would keep the negative charges inside the conductor, against their mutual repulsion?

We actually do produce beams of charged particles at accelerators, but we use magnetic fields to keep the beams focused. And the beams travel through vacuum, not through a conductor.
I’m not sure what would keep them together. I’m asking this question to see I there is some way of understanding how conductors work without having to have a strong understanding of how real world particles interact.

I was thinking through some non-electromagnetic force like the strong nuclear force, but I think that only holds the nucleus together, not difference molecules.
 
  • #7
jtbell said:
If a conductor had only negative charges and no positive charges, what would keep the negative charges inside the conductor, against their mutual repulsion?

We actually do produce beams of charged particles at accelerators, but we use magnetic fields to keep the beams focused. And the beams travel through vacuum, not through a conductor.
That's true. Electron beams can conduct over short distances (depending on how fast they are traveling and on ow well they are focussed at the start. But mutual repulsion will make any beam spread out eventually and a long beam of positive or negative carriers needs guiding and refocussing to keep it together. The 'old fashioned' Cathode Ray tube, as used in oscilloscopes and TV tubes did a pretty good job of producing a bright spot at the front of the tube, which shows that there has been Conduction from front to back (a few tens of cm).
FS98 said:
What are these abstract conductors made of?
I think we are all having a problem answering this particular part of your post. Apart from the "Charge Carriers" answer, there is little else to say about what an abstract conductor 'is'. Could you be a bit more specific? If you look https://en.wikipedia.org/wiki/Charged_particle it shows a list of charged particles that could carry a charge from A to B but they are not very practical if you were just after a 'conductor' in most cases. But, in other contexts - such as in an Aurora or lightning - there are naturally occurring currents flowing through a plasma.
 
  • #8
FS98 said:
I was thinking through some non-electromagnetic force like the strong nuclear force, but I think that only holds the nucleus together, not difference molecules.
You should try to avoid Word Salad when discussing these things. The world of particles is complicated enough, even when you apply the 'rules' as we know them. :smile:
 
  • Like
Likes FS98 and nsaspook
  • #9
sophiecentaur said:
You should try to avoid Word Salad when discussing these things. The world of particles is complicated enough, even when you apply the 'rules' as we know them. :smile:
What would be a simple definition of a conductor? When I look it up I find things like, a material that conducts electricity, or an object that allows the flow of current, but these definitions seem like they aren’t as useful as they could be.

Is there a definition that isn’t circular and doesn’t mention electricity? It feels like understanding electricity requires you to understand conductors, so these definitions make things confusing.
 
  • #10
FS98 said:
What would be a simple definition of a conductor?

sophie gave you a good answer in post #4 ...

sophiecentaur said:
Metals are excellent conductors, due to the highly mobile valence electrons.

Valence electrons of an atom are ones that are able to move between atoms. there are lots of them in, say, a piece of copper wire.
And when influenced by an electric field, they will start to move in a common direction, this is very basically what constitutes an electric currentDave
 
  • #11
FS98 said:
What would be a simple definition of a conductor? When I look it up I find things like, a material that conducts electricity, or an object that allows the flow of current, but these definitions seem like they aren’t as useful as they could be.

Is there a definition that isn’t circular and doesn’t mention electricity? It feels like understanding electricity requires you to understand conductors, so these definitions make things confusing.
Is there a definition of electrical conduction that doesn't mention electricity? No.

To get a toehold in the door leading to knowledge of what things can be an electrical conductor and why, look here.
https://en.wikipedia.org/wiki/Electrical_resistivity_and_conductivity#Causes_of_conductivity
 
  • #12
FS98 said:
What would be a simple definition of a conductor? When I look it up I find things like, a material that conducts electricity, or an object that allows the flow of current, but these definitions seem like they aren’t as useful as they could be.

Is there a definition that isn’t circular and doesn’t mention electricity? It feels like understanding electricity requires you to understand conductors, so these definitions make things confusing.

This whole topic is extremely confusing and puzzling. You are basically asking for a cake that isn't a cake, because you are asking for a conductor that isn't a conductor! It also appears as if you're asking for electric currents that isn't carried by charge particles. Can you see how odd this has looked so far?

Maybe, instead of asking for a "conductor", you should describe the properties or characteristics of exactly what you are looking for. The way things have been going so far, I don't think you even know what is involved in charge transport in solids.

Zz.
 
  • #13
ZapperZ said:
This whole topic is extremely confusing and puzzling. You are basically asking for a cake that isn't a cake, because you are asking for a conductor that isn't a conductor! It also appears as if you're asking for electric currents that isn't carried by charge particles. Can you see how odd this has looked so far?

Maybe, instead of asking for a "conductor", you should describe the properties or characteristics of exactly what you are looking for. The way things have been going so far, I don't think you even know what is involved in charge transport in solids.

Zz.
I don’t think I’m looking for a conductor that isn’t a conductor. I’m just curious about how conductors we’re understood before we knew about the electron. Maybe I’m wrong but I believe the idea of conductors did come first.

I understand that a metal is made of protons, neutrons, and electrons, and that the electrons can move freely throughout. I’m trying to understand how conductors we’re thought of before we had a solid understanding of what conductors were made of.
 
  • #14
FS98 said:
how conductors we’re thought of before we had a solid understanding of what conductors were made of.
It was treated as a macroscopic problem and the relationship between the Volts and Current was described as the Resistance. The exact nature of the 'electrical fluid' was not known (not knowable at the time) but that didn't interfere with appreciating the relationships. The model that followed gave the same results over a massive range of values.
I can't help thinking that your OP is going in the wrong direction, though. Science is essentially to do with making models that work and not with 'what things really are', as it used to be.
 
  • Like
Likes FS98 and Asymptotic
  • #15
FS98 said:
I’m trying to understand how conductors we’re thought of before we had a solid understanding of what conductors were made of.
Pretty much the same way that they're thought of today by electrical engineers, professional electricians, and in fact just about everybody except the subset of physicists who are working on the question "How does what we now know about the composition of matter explain what we've always known about the behavior of conductors?".

If you take a class on electrical circuits, you won't hear much about electrons and other subatomic particles. Instead you'll learn that electricity flows through some materials: we call these "conductors" and they have a property called "resistance" that obeys Ohm's law. That's how people have always thought about conductors; all that's changed since then is that we now have a better answer to the question "Why do conductors behave the way they do?"
 
Last edited:
  • Like
Likes FS98 and Asymptotic
  • #16
  • Like
Likes FS98

1. What materials can be used to make conductors?

Conductors can be made of various materials, including metals such as copper, silver, and aluminum, as well as alloys like brass and bronze. Other materials such as graphite and ionic solutions can also act as conductors.

2. Why are metals commonly used as conductors?

Metals are commonly used as conductors due to their high electrical conductivity. This means that they allow electricity to flow through them easily, making them ideal for applications where low resistance is needed.

3. Can any material be used as a conductor?

No, not all materials can be used as conductors. Insulators, such as rubber and plastic, do not allow electricity to flow through them easily and are therefore not suitable for use as conductors.

4. How do conductors differ from insulators?

Conductors and insulators differ in their ability to conduct electricity. Conductors allow electricity to flow through them, while insulators do not. Conductors also have low resistance, while insulators have high resistance.

5. Are there any other properties that conductors must have?

In addition to high electrical conductivity, conductors must also have physical properties that make them suitable for practical use. These include durability, flexibility, and resistance to corrosion and wear.

Suggested for: What Must Conductors be Made of

Replies
4
Views
11K
Replies
3
Views
1K
Replies
3
Views
2K
Replies
7
Views
2K
Replies
1
Views
760
Replies
11
Views
3K
Replies
84
Views
5K
Replies
4
Views
1K
Back
Top