Positive and Negative Charges

[Srah 1953]

Hi all
This is possibly a very stupid and basic question. Everything I've read says that electrons are negatively charged and protons positively charged and that opposite attract and so forth and that the movement of electrons constitute electric current. But what I've never seen explained is what the terms positively and negatively charged mean. I don't need this information for any practical purpose, just sheer curiosity.
Thanks

[colemj]

Electric charge is a quantized fundamental physical property of atomic particles like electrons and protons. And while Maxwell, Einstein and Bohr (and quite a few others) made wonderful and life-changing discoveries and predictions using this fundamental property, physicists are still at a loss to explain it fully and concisely and can only resort to describing it a little bit better using quarks and quasiparticles.

So it isn't a stupid question, although it is a basic one in the sense that the answer to it is a pillar of understanding of the nature of matter. Rest assured that the majority of physicists throughout history are, or were, asking the same question in one way or another.

Now, on to easier questions to answer, like "can I safely cruise a multihull on $500/month with my stainless swivels stored next to my Rocna and titanium barrel shotgun?"

Mark

[amytom]

Now to answer the question.

With equal quantities of electrons and protons the atom has no charge. If you take away electrons then it has a positive charge. If you add extra electrons it has a negative charge.

The negative terminal of the battery has more electrons than the positive terminal and they want to travel to the positive side to be equal again.

Of course that's the simple answer and there's quite a bit more involved.

[amytom]

Just reread the OP. Why are the electrons and protons themselves charged? Depends on what theory you're reading. Some believe it has to do with subatomic orbital spin others go deeper into string theory. What do I believe? I believe I'll go sailing.

[steve_hendry]

The terms positive and negative are arbitrary, invented by Ben Franklin (xkcd: Urgent Mission).

[GordMay]

Wikipedia has a reasonably coherent explanation.
Here ➥ Electric charge - Wikipedia, the free encyclopedia

[sailorboy1]

It's all just PFM!

This answer will just make your life a lot easier!

[Srah 1953]

Looking up the Wikipedia entry referenced by GordMay, we have the following-
“The electrical properties of the two pieces of glass are similar to each other but opposite to those of the two pieces of resin: the glass attracts what the resin repels and repels what the resin attracts.
If a body electrified in any manner whatever behaves as the glass does, that is, if it repels the glass and attracts the resin, the body is said to be 'vitreously' electrified, and if it attracts the glass and repels the resin it is said to be 'resinously' electrified. All electrified bodies are found to be either vitreously or resinously electrified.
It is the established convention of the scientific community to define the vitreous electrification as positive, and the resinous electrification as negative. The exactly opposite properties of the two kinds of electrification justify us in indicating them by opposite signs, but the application of the positive sign to one rather than to the other kind must be considered as a matter of arbitrary convention, just as it is a matter of convention in mathematical diagram to reckon positive distances towards the right hand.”

If, having read something, you can't explain it to somebody else, then you haven't really understood it and I wouldn't be able to explain the above in any meaningful way to a third party! But still, I'm getting there.


Amytom said, inter alia, the following “The negative terminal of the battery has more electrons than the positive terminal and they want to travel to the positive side to be equal again.”
Why do they go the long way round the circuit rather than taking the shortcut through the battery? In fact, if there was a surfeit of electrons on the negative side, surely they wouldn't need a circuit, they would just flow through the eloctrolyte to the positive side?
Looking back at one of my books on the subject, it is stated that it is the potential voltage, or is it voltage potential, that causes the electrons to flow. I don't really understand voltage potential either other than if you place the probes of a multimeter you can get a meaningful reading.
Cheers

[Srah 1953]

I should have said, in the words of the meerkat, "SIMPLES", but I don't know how far that phrase has travelled.............

[DeepFrz]

Why are the electrons and protons themselves charged?

Because the gods wanted them that way?

[pumpcity]

"In fact, if there was a surfeit of electrons on the negative side, surely they wouldn't need a circuit, they would just flow through the eloctrolyte to the positive side?"

There is an insulator between positive and negative to prevent that from happening. A voltage potential is caused by a differential in electrical charge. Are you saying that you can see no possible way to insulate between the two parts of the differential to prevent a release of charge within the battery? Is that true of all batteries?

[Bergovoy]

omg, this discussion sounds so exactly like the other one last month. even the question/op, phrased it the same way... i gotta find that discussion... to check my memory...

[amytom]

Originally Posted by Srah 1953

Amytom said, inter alia, the following “The negative terminal of the battery has more electrons than the positive terminal and they want to travel to the positive side to be equal again.”
Why do they go the long way round the circuit rather than taking the shortcut through the battery? In fact, if there was a surfeit of electrons on the negative side, surely they wouldn't need a circuit, they would just flow through the eloctrolyte to the positive side?
Looking back at one of my books on the subject, it is stated that it is the potential voltage, or is it voltage potential, that causes the electrons to flow. I don't really understand voltage potential either other than if you place the probes of a multimeter you can get a meaningful reading.
Cheers

Because the acid is working against the dissimilar metals on the two terminals of the battery. This creates the difference in electrons (difference in potential). In a generator or alternator the moving magnetic field does the same thing against a coil of wire.

Electrical engineering is a 5 year degree and too many people walking around with that piece of paper can't quite explain it either.

In the Navy we drew a PFM button on our desks. When we asked too deep of questions the instructor would have us push the button.

[Bergovoy]

http://www.cruisersforum.com/forums/...rgy-51865.html

ok, the OP didnt phrase it the same but there is a couple messages in that discussion that do kinda use similar phrasing...


but to summarize, like what was stated above, positive and negative are names made up by Frankliln, and the correct terminology wold be POTENTIAL... and things are referenced to a common , not necesarily GROUND... ground is different for differnt things, and different types of electricity, i.e. ac vs dc...

and electons dont flow.. they are passed and shared... if an atom has enough electrons and one is nearby, that electron maybe shared, and then the atom has too many electrons, making it easy to share one with a nearby atom, (copper atom for conductors, or aluminum, etc)...

electrons are pushed, they are drawn, so the source is a 'capacity' to share electrons...

battery terminals dont have extra electrons, on one side or the other, but the battery has a way of producing electrons, it has potential to use the acids and anodes and cathodes to create flow in a kind of perpetual motion type of way, although it isnt forever as you know as the parts wear down. chemicals weaken, metals deteriorate, etc...

but when a circuit is created where the electrons can be produced and flow from the negative to the positive, the cycle will repeat...

if there wasnt loss of efficiency, i.e. heat, or resistance, then the electrons would flow for a very long time... yes, i used the word flow, for simplicity reasons...

also, electrons dont 'flow' because of opposites attract or something lke that. but rather to go from one side or a potiential to the other... like a pendulum will have more potential when raised on one side, it will want to swing to the other side, not because of magnetism or other rules of attraction, but more of a balancing of the potential energies...

and again, that is another analogy that isnt quite the same thing but the concept may help to understand that things happen similary for different reason..

[DeepFrz]

P.F.M. (Premiata Forneria Marconi)?