# Is my understanding of electric fields accurate?

Could someone please help me and let me know if the statements below are any accurate? I am struggling trying to understand what electric fields are and I could really use some help!

1. An electric field is a force that radiates away from protons and towards electrons.

2. Because atoms are the basic building blocks of ordinary matter, electric fields are always associated with atoms. In other words, we never refer to electric fields as being generated by lonely protons or lonely electrons floating somewhere in space, instead, we always refer to the electric field in atoms. That said, we could redefine statement 1 and say that an electric field is a force that radiates away from atoms with a lack of electrons and towards atoms with an excess of electrons.

3. Under normal conditions, the electric field between the atom’s protons and the atom’s electrons cancels out. When this happens, the atom is neutral (no charge), no electric field radiates in or out of the atom.

4. Under not so normal conditions, an atom will either lack electrons or have excess electrons, when this happens a "push and pull" electric field is formed between the atoms. This "push and pull" field is what makes electrons move from the negatively charged atom to the positively charge atom creating electric current.

5. As mentione before, an "push and pull" electric field is created between atom that lack electrons and those that have excess electrons, it does not matter what type of atoms they are, for example, if one atom of Oxygen is missing an electron and one atom of Calcium has an extra electron then an electric field will form between those atoms.

6. Electric fields are infinite. This means that an electric field will be formed between atoms with lack of electrons and atoms with excess electrons no matter how far apart they are. To be clear, even if the atoms are billions and billions of miles apart there will still be an electric field formed between them.

7. An electric field that forms between two atoms is what makes voltage happen. The closer the atoms are from each other the greater the voltage will be between them duet to thicker flux lines crossing each other.

Do my statements make any sense whatsoever or am I just embarrassing myself?

Thank you.

• There are too many stuff in this question. For the physics stacke exchange format, it is better to split this question up and ask several questions. – Cicero Jun 3 '15 at 22:24
• All but 1 and 2 are essentially correct. Electric fields are created by any charged particle (and also by changing magnetic fields). – Javier Jun 3 '15 at 22:53

## 1 Answer

Do my statements make any sense whatsoever or am I just embarrassing myself?

First of all, never be embarrased asking a question :) Though a quite long question, I will quickly go through your points:

1. An electric field is a force that radiates away from protons and towards electrons.

No, electric field and force is not the same. But you could though consider it a "force per charge", since they are related by $E=F/q$.

"Radiates" away is not a proper term. There is no radiation here.

Yes, the direction is correct (just a convention). But remember that this "direction" is just to tell the orientation of the effect the field might cause. If you put a positive charge in an electric field, it will be pushed along with the field line direction (because of the force in $E=F/q$); if you put a negative charge in, it will move the opposite way.

1. Because atoms are the basic building blocks of ordinary matter, electric fields are always associated with atoms. In other words, we never refer to electric fields as being generated by lonely protons or lonely electrons floating somewhere in space, instead, we always refer to the electric field in atoms. That said, we could redefine statement 1 and say that an electric field is a force that radiates away from atoms with a lack of electrons and towards atoms with an excess of electrons.

With the above corrections, yes, this will be the orientation of ions (charges atoms that are missing or have extra electrons).

But saying that "electric fields are always associated with atoms" is simply not true. In many cases in nature do we consider single positive or negative charges. For examples, consider semiconductor materials that are essential for much electronics, solar panels etc.

1. Under normal conditions, the electric field between the atom’s protons and the atom’s electrons cancels out. When this happens, the atom is neutral (no charge), no electric field radiates in or out of the atom.

Correct.

1. Under not so normal conditions, an atom will either lack electrons or have excess electrons, when this happens a "push and pull" electric field is formed between the atoms. This "push and pull" field is what makes electrons move from the negatively charged atom to the positively charge atom creating electric current.

Correct. Usually in a conducting wire for example, we don't consider the atomic structure but just the many free electrons. Yes, they are each associated with a mother-atom, but the "sea" of electrons that can concentrate in one end, causing an electric field, is usually described as what causes current to flow.

1. As mentione before, an "push and pull" electric field is created between atom that lack electrons and those that have excess electrons, it does not matter what type of atoms they are, for example, if one atom of Oxygen is missing an electron and one atom of Calcium has an extra electron then an electric field will form between those atoms.

Correct. A note: if you look at two seperated ions (charged atoms) they behave like this. If you on the contrary considers a bonding between two atoms where they share an electron pair e.g., then this pair is not necessarily positioned exactly in the middle in between the two ions. Because of the "shape" of the atom and how tightly held the electron shells are, ions have different electronegativity - when you break a bond, the most electronegative atom is the one that will keep the electrons.

So, what you say is true, but if you get very close to the atoms or even mix the electron waves of two atoms, the distances to the positive cores and the remaining electrons of each atom makes it much more complicated, as you cannot just consider it a simple point-charge anymore. This is a topic of chemical bonds and only relevant in compounds.

1. Electric fields are infinite. This means that an electric field will be formed between atoms with lack of electrons and atoms with excess electrons no matter how far apart they are. To be clear, even if the atoms are billions and billions of miles apart there will still be an electric field formed between them.

Correct.

Another note: You always refer to two charged atoms at a time. While what you say is correct, it would still be true for just a single charge in space. This charge will by itself cause an electric field in it's surroundings theoretically spanning to infinity.

1. An electric field that forms between two atoms is what makes voltage happen. The closer the atoms are from each other the greater the voltage will be between them duet to thicker flux lines crossing each other.

Sort of correct. But let's clear one thing out here: What is voltage exactly?

Voltage is another word for difference in electric potential. Each point in space will have an electric potential is there is a charge somewhere. Electric potential $V$ is simply electric potential energy $U$ per charge $q$ that is located at that point and being pushed at, $V=U/q$.

A charge wants to move to a point of lower (electric) potential energy. Just like a ball on a high shelf will tend to roll down to lower (gravitational) potential energy. Electric potential can be found by:

$$V=\frac{1}{4 \pi \epsilon_0} \frac{Q}{r}$$

$Q$ is the charge that causes the field (not the charge that is being pushed at). If there is much negative charge in one area (like close to a negative ion) you will find the potential to be negative $V_n<0$ since the charge is negative, $q=-e$. Close to a positive charge the potential is positive $V_p>0$.

• Now, postiive charge will have negative potential energy at a point of negative potential, because of $V=U/q$ (where you multiply the negative $V$ with the positive $q$). It will have positive potential energy at a point of positive potential. So it wants to move to the negative potential (towards the negative charge).

• A negative charge on the contrary will have the highest potential energy at a point of negative potential. Again because of $V=U/q$ (you multiply the negative $V$ with the now negative $q$). So for the electron, the point of lowest potential energy is at the point positive potential, and it will move towards the positive charge.

And now, back to the term voltage $V$. Voltage simply means potential difference, $V= V_p-V_n$. making voltage happen is again an odd choice of words - voltage doesn't "happen", voltage just "is". And if you added a charge in this field it would move, which we can determine if we know the voltage.

Lastly, yes, voltage and electric field are related by $E=V/r$, where $r$ is the distance between the two points over which the voltage (caused by the field $E$) is measured.