0
$\begingroup$

I am studying electricity and until about now I never really gave much thought to the statement that equal number of proton and electron means neutral charge. Like if we simplify the question and consider two point charges, one is positive and another negative, exactly what is happening to the electric field produced by the individual positive and negative charges that when they attract each other, we say that there is no charge? Like does the respective electric field produced by them disappear? What exactly does neutral charge mean? Do neutral objects that have equal number of proton and electron no longer feel electric field?

$\endgroup$
1

2 Answers 2

1
$\begingroup$

exactly what is happening to the electric field produced by the individuals positive and negative charge that when they attract each other, we say that there is no charge?

If the amount of positive and negative charge is equal, then the net charge is zero. That is not the same thing as saying there is no charge.

Like does the respective electric field produced by them disappear?

No. Those fields don't "disappear".

For example, if another negative charge were brought nearby it would experience an attractive force by the field of the positive point charge and a repulsive force by the field of the negative point charge.

What exactly does neutral charge mean?

Simply that the amount of positive and negative charge is equal.

Do neutral objects that have equal number of proton and electron no longer feel electric field?

I assume you are asking if the neutral object would "feel" an electric field produced by some other negatively (or positively) charged object. That would depend on how the positive and negative charges are distributed on the neutral object.

For example polar molecules, where the charge distribution is spherically asymmetrical (resulting in a dipole moment), such as water, will interact with an external electric field causing it to rotate, whereas non polar molecules where the charge distribution is spherically symmetrical, such as carbon dioxide, will not interact with electric fields.

Hope this helps.

$\endgroup$
0
$\begingroup$

Additional to Bob D's answer:

Neutral atom - dipole moment

Two point electric charges separated by a small distance will have an electric field that is not zero. This is called a dipole moment The field far from the dipole tends rapidly toward zero (It falls off as $\frac {1}{r^3}$).
One definition of "neutral" could be supplied by Gauss' Law which states that the integral of flux through a closed surface is proportional to the total charge enclosed, indicating that this integral will be zero for an equal distribution of positive and negative charges enclosed by the surface.

Atoms have their own dipole moment, even though the electron charge is “smeared out” in a cloud around the proton due to QM. see this pdf

The best example of this is the water molecule which has a pronounced dipole moment responsible for the exceptional properties of water, for example its very large latent heat of evaporation compared to other common liquids.

Neutral atoms in an electric field will be affected by it. For example if the field is strong enough the electron may be pulled away from a hydrogen atom (Needs to be extremely strong!). All of chemistry is determined by the interaction of the electric fields of atoms. (Note to chemists; I know there is a lot more involved such as Gibb's Free Energy) For example, two neutral hydrogen atoms will bond to force a $H_2$ molecule, where the two electrons are shared by the two protons.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.