Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Questions about electrically neutral atoms!

  1. Jul 7, 2013 #1
    Hi, everybody. I wanted to ask you about the question that really tortured me for quite a long time: Does electrically neutral atom have energy above 0?
    I mean what would happen if you have measuring instruments and they tell you energy is 0, but the energy of atom is still there-potential energy?

    Do electrically neutral atoms have/possess any kind of energy field, or any kind of force field that surrounds them, or atoms are truly empty (except the core, the rest, 99.94% of atom is empty)?
    I'm talking about electric energy, magnetic field, electromagnetic field, quantum field or whatever

    But is there such thing as being truly empty even if atom is electrically neutral? But as far as I know, 100% nothingness/emptiness does not exist (not even inside of atom), so how to explain the void/emptiness in the atom (I'm talking about those 99.94% that are empty and the rest is the core which is not empty)?
    Are those 99.94% of the atom truly empty or they are filled with some energy field of force field?

    Could you say the charge of atom is 0 (when you measure it), but it's still there perfectly balanced in electrons, and protons?
    Could you say the energy of atom is 0 (when you measure it), but it's still there in electrons, and protons, actually it's only perfectly balanced?

    Is it true that the electric field of a neutral atom is weak, but is not exactly zero because the atom is not a point particle-i saw this here:
    http://sciencequestionswithchris.wordpress.com/2013/06/07/why-do-atoms-always-contain-the-same-number-of-electrons-and-protons/ [Broken]

    Didn't you hear that atom has been seen, literally?

    Big thanks in advance to all your answers, explanations, time and patience!
    Last edited by a moderator: May 6, 2017
  2. jcsd
  3. Jul 7, 2013 #2

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper


    Yes. The atom in it's ground state does not have energy zero ... it has internal energy usually called it's binding energy.

    Yes. It is possible to add an electron to a neutral atom to make it negatively charged. Many atoms are stable in this configuration - how would the electron stay there if there were no field of some kind?

    The "emptyness" is full of electromagnetic field/energy.

    There is a difference between having a charge of zero and having a net charge of zero - atoms are neutral but their components are not, and this shows up when probes get very close to them or they are subject to an outside electric field.

    An electromagnetic potential is only zero with respect to some other reference point. You have to say how you are measuring the energy for questions like that to make sense.

    That would be correct - it's down to quantum.

    However, even classical systems can be like this. Look at the field due to an electric dipole, for instance. Here you have +q and -q separated by a distance - the system has net neutral charge but there is a non-zero electric field.

    In the planetary model of an atom - the electrons "orbit" the nucleus.
    An electron going in a circle is an electric current loop.
    An electric current loop is a magnet ... and so are atoms.

    ... for a particular definition of "seen", yep.
    But no amount of squinting will work.

    You seem to be trying to understand atoms using classical electrostatics - don't:
    1. atoms are not static systems
    2. atoms are not well described by classical physics
    ... it's no wonder you are having trouble.
  4. Jul 8, 2013 #3
    You said:
    "An electromagnetic potential is only zero with respect to some other reference point. You have to say how you are measuring the energy for questions like that to make sense."

    Sorry, but I'm a bit confused with the answer, I hope you wouldn't mind to be more specific on what you meant to say, since I have to say I didn't really understand the answer.
    Sorry for this.

    You also said:
    "Yes. It is possible to add an electron to a neutral atom to make it negatively charged. Many atoms are stable in this configuration - how would the electron stay there if there were no field of some kind?"

    So basically electromagnetic field of electrically neutral atom (without adding or taking any electrons or protons or neutrons) enables electron to stay inside the atom?

    Do fields actually create forces (like electromagnetic energy creates electromagnetic force, strong/weak nuclear energy creates strong/weak nuclear force, gravitational energy creates gravitational force or is it the mass)?
    Than what creates forces-these energies for example?

    Generally speaking, does energy creates force or force creates energy, is energy a form of force or force is a form of energy, or is it something third, how does this work?

    Ok, I'm a bit confused, are you talking about electrical field or electromagnetic field of atom when electric charge is 0?
    What does create electric or electromagnetic fields, strong nuclear force,weak nuclear force, is it energy or something connected with energy (directly or indirectly)?

    And does energy create force or it is the opposite (in both classic and quantum physics)?
    If you need to answer when it comes quantum physics (since I have included either classsic physics and quantum physics explanation about the question if energy creates force or it is the opposite, I don't want to be banned because of the dumb mistake from my side), you can answer here:

    I hope my questions have some sense!?
    Again, big thank you in advance for all of your answers, time and patience.
    Last edited: Jul 8, 2013
  5. Jul 8, 2013 #4

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper

    Basically it is not clear what you mean by "energy" in your questions - from what you say, you appear to be talking about electric potential energy.

    There is no absolute zero for potential energy.
    Look up "potential energy".

    Each positive charge attracts all the negative charges around it ...

    The force carrier for the electromagnetic field is the photon.
    The "field" is a way of describing how force changes with position.

    The force is the change in momentum ... we don't usually think of force and energy as one "creating" the other, they are both ways of describing the physics. In particle physics, forces are treated as a manifestation of the transfer of energy.

    Like I said - you appear to be trying to understand electrodynamics using inadequate tools.
    On top of that, you don't appear to be using very precise terms.
    Thus: it is not surprising you are getting confused.

    What level do you want the explanations at?

    Aside: notice how I have edited the quote so my answers go right after your questions?
    You can do that too ... just put /quote tags in where you need a break.
  6. Jul 9, 2013 #5
    Most likely I'm, thanks for the tip.

    S what would happen if there were no fields? The force would not be changed with position, what would it mean for the world and the universe?

    Ok, thanks, I should ask on Quantum physics forum, how are forces treated on quantum level.

    I see, I should find some very good book about electrodynamics.

    Ok, thanks, but what do you mean by:
    "What level do you want the explanations at?"

    Are you asking me if I want explanations from quantum physics or atomic physics?
    If that's what you're asking me why not both (if you have time).
    I'm not sure if I understood this question well.

    I do admit I'm awkward with these questions, mostly because I'm not sure how to ask right.
    And of course I'll look for those terms for potential energy and force-but is wikipedia enough or you perhaps know websites that are more precise and more detailed in their explanations?
    Last edited: Jul 9, 2013
  7. Jul 9, 2013 #6

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper

    There would be no Universe. No fields means there is nothing to describe.

    At the quantum level we talk about "interactions"... the interactions can change the momentum of a particle which is considered as a transition between quantum states. The rate of change of momentum (a force) does not have any meaning for a single interaction.

    YOu could get away with looking for online courses ... if they seem too hard, look for earlier courses until you hit something you relate to and start there.

    Education level.
    You seem to be asking these questions from the point of view of someone beginning at secondary school who has done a lot of pop-science reading and viewing... but that's just a guess. Many of the answers, to be complete, require post-grad college level. But if I give you those, will you understand them?
  8. Jul 10, 2013 #7
    Well I do study general physics on the college, I don't know if that's enough, my posts usually are a mess, that's my problem with expressing myself, I'm trying to be simple, but than I get too complicated and get lost in what I wrote.
    I also have huge concentration problems, and because of that I need more time to understand than usual.
  9. Jul 10, 2013 #8

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper

    What does "general physics" mean? What level in University is it (prep, year 1, year 2, year 3, post-grad, what)? Is it part of a degree course? Did you complete (and pass) a secondary level physics course?

    Note: there is no judgement on any of this - we all have to start somewhere, we all have our difficulties and talents. If I don't know where you are at, I cannot answer your questions in a way that you will understand.

    You will need to get a handle on your communication and concentration issue, you won't advance in University otherwise.
  10. Jul 10, 2013 #9
    Sorry for misinformation, I'm now finishing the 1st year (barely).
    It's really hard for me regarding mentioned issues, but I'm not giving up, and I actually like physics.
    My great problem is that I can forget some fundamental things in physics so I have to remind myself every single day.
  11. Jul 10, 2013 #10

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper

    Atomic behavior is not going to be easy to understand with sophmore electromagnetism - it's still treated as two separate subjects, at that evel, in many universities. However, you should have been introduced the the Bohr atom and the concept of atomic orbitals? Maybe the shell model for atoms? You should have had examples of atoms being ionized?

    You should also have been introduced to the idea that electrically neutral macroscopic objects can carry an excess positive or negative charge? And you should have done calculations of forces between charges where they are not moving?

    All this should give you an idea about how I've answered your questions.
    You should review your course notes from the last year to help you refine your questions and gain more focus.
  12. Jul 11, 2013 #11
    Yes, you're right, I'm checking right now (I started yesterday evening). It does becoming with more sense now.
    It's good I never throw lectures, and of course, the books.
    So, no worries, I guess I simply needed a reminder of this.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook