# What is charge? i know that it is of two types positive and

1. Jul 21, 2011

### nouveau_riche

what is charge?
i know that it is of two types positive and negative, i need the physical interpretation

and it would be really helpful if anyone can tell something about the history of discovery of charge,well i know about the discovery of electrons and all that ,what i am interested in is how the physicist could make something as anode/cathode if they were discovering the nature of cathode rays?

2. Jul 21, 2011

### Drakkith

Staff Emeritus
Re: charge

Electric Charge: http://en.wikipedia.org/wiki/Electric_charge

I don't really know what you are asking for with your 2nd question. An anode/cathose is simply a charged object such as a metal plate. It was known about long before the discovery of the electron.

3. Jul 21, 2011

### Studiot

Re: charge

I posted this in post#21 of this thread

So try this.

Charge, like mass, is a property of matter.
It is more complicated than mass because simple experiments show that there are two types or polarities.
All matter possesses mass, but not all matter possesses charge.

Experiments show that uncharged (neutral) matter exerts a force of attraction between two masses and that this force is governed by the inverse square law. We call this gravitational attraction.

Work is therefore done on the mass of any matter moved against this force.

Further experiments show that an additional force exists between charged matter, over and above that exerted by gravity. It is further observed that the direction of this force depends upon the relative polarities of the participating charges. We call this electrostatic attraction or repulsion.

Work is therefore done on the mass of any matter that we move against this force.

It is often stated, rather loosely, that work is done on the charge. This is not so. Work is done on the mass of the matter. So you will find the mass of the charged particle appear in many equations.

It just so happens that the units chosen hide this so the standard definition of the volt, referred to by Sophie Centaur is defined in terms of a force exerted by a fixed number of electrons and a distance. In other words our units of charge incorporate a mass term.

hope it helps.

4. Jul 21, 2011

### That Neuron

Re: charge

Yeah, pretty much everything Studiot said is correct, I would also just like to point out the connection between magnetism and electricity...which gives rise to electromagnetic charge. And also like gravity charge propagates through the inverse square law.

But what I would like to ask, is if charge is a property arising from the various groups and interactions of elementary particles, or does it only appear in the hydron? (with the exception of electron)

5. Jul 21, 2011

### Drakkith

Staff Emeritus
Re: charge

Charge is a property of matter. An electron has a negative charge while a proton has a positive charge. Whether or not these particles are in atoms matters not. There are other charged particles as well, but none are stable.

6. Jul 22, 2011

### nouveau_riche

Re: charge

as you say about anode/cathode(that it was known of them long before discovery of electron)
but how were anode/cathode discovered?

7. Jul 22, 2011

### Dickfore

Re: charge

Please enroll in a course on Electromagnetism at your local higher education Institution.

8. Jul 22, 2011

### nouveau_riche

Re: charge

if you are enrolled already,you can be of some help i guess

9. Jul 22, 2011

### Dickfore

Re: charge

To answer your question, one needs to write a long text the size of a term report. Since I am not getting any marks for this, I think I will skip the opportunity.

10. Jul 22, 2011

### nouveau_riche

Re: charge

so must not post any comment here,because no one is going to give you marks

11. Jul 22, 2011

### Dickfore

Re: charge

It's one thing to post one or two paragraphs worth of an answer that would relate to a question that is sufficiently narrow in breadth and put in a succinct form, but it's another thing to write you a term paper on a broad subject. It's like saying: "I don't understand what Quantum Mechanics is. It would be helpful if someone could say something about the history of the development of the theory, the fundamental experiments that were performed and the people who are authorities on the matter. Thank you."

12. Jul 22, 2011

### nouveau_riche

Re: charge

my demand was to put a historical background for that,if you know it,you can abstract that out and if you don't ,say that aloud

13. Jul 22, 2011

### Dickfore

Re: charge

Taken from http://en.wikipedia.org/wiki/Electric_charge#History

14. Jul 22, 2011

### Staff: Mentor

Re: charge

In addition to the link on charge there is also this link on the history of electrochemical cells:
http://en.wikipedia.org/wiki/History_of_the_battery

For historical questions like this you will get better answers from Wikipedia than from PF. As Dickfore mentioned, a good treatment of history tends to be rather lengthy and not terribly suitable for someone to produce as a post on a forum.

Do you have further questions about the physics?

15. Jul 22, 2011