What is the net charge and why does it matter?

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Discussion Overview

The discussion revolves around the concept of electric charge, specifically focusing on the definition of neutral particles and the implications of net charge in atomic systems. Participants explore the nature of electric fields in relation to charged and neutral particles, as well as the behavior of atoms in classical and quantum contexts.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • Some participants define a neutral particle as one with no electric charge, while others specify it must have no net electric charge.
  • There is a discussion about whether an atom can be considered neutral despite the separation of its charged components (protons and electrons), with some arguing that this separation implies a non-neutral state.
  • One participant suggests that if an atom has a net charge of zero, it should not have an electric field around it, while others challenge this view by citing examples such as dipoles, which can have zero net charge but still possess an electric field.
  • Some participants emphasize the importance of distinguishing between classical and quantum mechanical descriptions of atomic structure, noting that the electron's position is not fixed in a quantum model.
  • There is a contention regarding the implications of having a net charge of zero and whether it necessarily leads to the absence of an electric field, with participants providing differing interpretations and examples.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the relationship between net charge and the presence of an electric field. Multiple competing views remain regarding the definitions and implications of neutrality in particles and atomic systems.

Contextual Notes

Some participants' arguments depend on classical interpretations of particles and fields, while others invoke quantum mechanics, leading to potential misunderstandings based on differing foundational assumptions.

  • #61
Cthugha said:
That does not matter. Draw a circle around your system and count all the charges inside. The number you get is your net charge and here it is zero.

I have replied, why I don't agree net charge is zero here. Please read it, if you find I am wrong there, pardon me and explain where I am wrong.

The position or separation does NOT matter. This is your very own definition nobody else uses. You cannot expect people to help you if you make up your own language.

If you think I have created my own definition, please specify which one I have created. And please provide correct definition for it (with reference, from where you have got that definition).
 
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  • #62
CURIE WILLEY said:
@DOC AL. Thank you for the reply, Sir. If we have +1 charge in one hand and -1 charge in the other hand, net charge will not be zero (as distance of separation is not zero).
False. Until you correct this statement, there's not much point of going any further. The net charge will be zero regardless of the distance.
 
  • #63
CURIE WILLEY said:
According to coulombs law, force between the charges is given by the equation

##F=\frac{1}{4∏ε}.\frac{q_1q_2}{r^2}##

If ##q_2## has net charge zero, it can't exert force on other charge according to me, because it has no electric field around it.


Yes if q2 is not exerting force then it can never be charged PARTICLE(remember you are saying it on the basic of Coulomb's law which is valid for point charges). But what if this is not a point,sized charged particle but a collection of charged particles(like dipole or hydrogen atom- on which you are trying to apply the definition of charge while they are not charge, for charge is exclusively the property of a(certain sub-atomic) particles you should not apply it for collection of charge))or matter with charge particles.
Do you think Coulomb would allow to use his law under such case?
 
Last edited:
  • #64
@DOC AL. Thank you for the reply, Sir. If we have +1 charge in one hand and -1 charge in the other hand, net charge will not be zero (as distance of separation is not zero).

Doc Al said:
False. Until you correct this statement, there's not much point of going any further. The net charge will be zero regardless of the distance.

If distance of separation between the opposite charges of the dipole is zero, electric field around the system will be zero. As said always, according to me, if field is zero, net charge is zero. If distance of separation between the opposite charges is non-zero, there exists field. So, according to me, if field is non-zero, net charge is non-zero.

This has been disagreed, saying definitions of wiki is wrong. If they are wrong, it would be appreciable if correct definitions are provided (with reference, from where that definition has been extracted).

I think we are in need of knowing what actually is net charge?

So, if any particular definition from any particular reference would be appreciable. I have provided my opinion on the basis of wiki, but they are said be incorrect. So, there is a need of knowing correct definitions.
 
  • #65
Closed, pending moderation.

Zz.
 
  • #66
CURIE WILLEY said:
This has been disagreed, saying definitions of wiki is wrong. If they are wrong, it would be appreciable if correct definitions are provided (with reference, from where that definition has been extracted).

I think we are in need of knowing what actually is net charge?
The definition of net charge was given by Doc Al in post 10.
Doc Al said:
Net charge being zero simply means that the total charge (just add 'em up) is zero: \Sigma q_i = 0
For references there are the following academic links:
http://www.physics.sjsu.edu/becker/physics51/elec_charge.htm
http://web.mit.edu/viz/EM/visualizations/coursenotes/modules/guide02.pdf

Although it should be obvious. The term "net" simply means the sum. So your "net income" is the sum of all of your sources of income less any deductions to your income. Similarly, "net force" on an object is the sum of all forces acting on the object. Similarly, "net charge" is the sum of all the charges.

Note that ##E=k\Sigma (q_i/r_i^2) \mathbf{\hat r}## can be non-zero even if ##\Sigma q_i## is zero. Your reasoning is simply wrong, as was pointed out to you many times.
 

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