What does it mean for somthing to become ionized?

Discussion in 'Chemistry' started by skaught, Dec 1, 2008.

  1. skaught The field its covered in blood Valued Senior Member

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    Rather, can someone explain this to me?
    From wikipedia:

    Traditionally, three states of matter are recognized: solid, which maintains a fixed volume and shape; liquid, which maintains a fixed volume but adopts the shape of its container; and gas, which occupies the entire volume available. Plasma, or ionized gas, is a fourth state and occurs at high temperatures.
     
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  3. James R Just this guy, you know? Staff Member

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    An ionized atom is usually one that has lost one or more electrons.

    For example, an oxygen atom usually has 8 electrons. If it loses one, then it is represented as \(O^+\). If it loses 2, then we have \(O^{2+}\). The plus signs are because the atom now has an overall positive charge.

    Negative ions also exist, where an atom gains one or more electrons compared to its normal number. And example would be a chlorine atom with one extra electron, which would be \(Cl^-\).
     
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  5. skaught The field its covered in blood Valued Senior Member

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    So how could or would an atom gain or loose an electron?
     
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  7. skaught The field its covered in blood Valued Senior Member

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    So how does something like hydrogen become helium? Is helium just ionized hydrogen?
     
  8. Trippy ALEA IACTA EST Staff Member

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    So here's how it works.
    All of the atoms of the periodic table prefer to have either full, or half full shells of electrons, because those are the most energetically stable.

    Those with full electron shells are isoelectronic with the Noble Gasses.

    Take Hydrogen.

    It can react by gaining, or loosing an electron.
    In loosing an electron, it becomes a bare proton.
    In gaining an electron it becomes the Hydride anion, and has two electrons in it, just the same as Helium.

    Within the first 20 elements, the trend is to react to become isoelectronic with a noble gasses. The metals do this by loosing electrons, and the non metals do this by gaining electrons.

    Why this should be the case has to do with the effective nuclear charge experienced by the outer most electrons. Essentially, those electrons in shells 'below' the outermost shell block the positive charge of the nucleus more effectively than those other electrons in the same shell. This is why the group 1 and group 17 elements are the most reactive. The outer electrons of the group one elements experience the lowest attraction to the nucleus, therefore, on each row, they're the most easily lost, which is also why Group 1 reactivity increases as you move down the group.

    Group 17 elements are the most reactive non-metals because their outer electrons feel the strongest attraction to the nucleus in that row, because the number of 'blocking' electrons is the same, but there's more protons there now. This same attraction also applies to the outer electrons of other atoms.

    Things get more complicated with metalloids, and because it turns out that half full electron shells can be stable to.

    And no, Helium isn't just ionized hydrogen. Helium has 2 protons, and 2 neutrons, where as Hydrogen only has 1 Proton (ignoring isotopes).

    To demonstrate this point, Hydrogen-3 has 1 proton, and two neutrons, but Helium 3 has 2 protons and one neutron. The weigh the same, but chemically, are very very different.

    In plasmas, because they're very high energy environments, because it turns out it's easy to strip electrons off an atom by smacking another one into it hard enough, but it's not so easy to make an extra electron stick.

    As an example of everything i've been talking about, see the Wikipedia entry on Ionization Potential: http://en.wikipedia.org/wiki/First_ionization_energy
     
  9. skaught The field its covered in blood Valued Senior Member

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    Wow! Thank you trippy!
     
  10. Fraggle Rocker Staff Member

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    "Ionization" also refers to the separation of the atoms that comprise a molecule. This can happen at high temperatures, which is how you create plasma. But outside the laboratory it happens commonly when a substance is dissolved in water or some other solvent.

    Table salt is sodium chloride, NaCl. Each molecule of salt has one sodium atom and one chlorine atom. The outer orbit of the sodium atom only has one lonely electron, and the outer orbit of the chlorine atom contains seven electrons who are eager to find an eighth one to complete their orbit. The two atoms hook up and the single electron moves over to the now-happy chlorine atom. The resulting positive electrical charge on the sodium atom (it's missing an electron so now it has too many protons in its nucleus) attracts it to the chlorine atom, which now has an extra electron in its outer orbit and therefore a negative electrical charge.

    This is all great when you're staring at a pile of solid salt on your spoon. But when you dump that salt into a cup of water, it dissolves and the individual sodium chloride molecules separate and start floating around aimlessly. But it goes beyond that. The individual sodium and chlorine atoms even separate from each other, so the molecules basically don't exist any more.

    But... there's a catch. The chlorine atom hangs on to the extra electron it borrowed from the sodium atom, because it's so happy to have its outer orbit completed. And the sodium atom is just as happy to be rid of that extra electron anyway, because now it has nothing but complete orbits.

    So we've got sodium ions and chlorine ions in the water. Each of them is just a normal atom of that element, except for the fact that it has one less or one more electron than it's supposed to have. The sodium ion is a positive ion because it has one more proton than electrons and has a positive electrical charge. The chlorine ion is a negative ion for a similar reason.

    This type of ionization occurs at room temperature, in fact it can occur at very cold temperatures. You can put your cup of soup in the refrigerator and let it cool down almost to the freezing point, and the sodium and chlorine atoms in the salt are still ionized.

    You don't have to create plasma in order to have ionization occur. It's all around you.
     
  11. skaught The field its covered in blood Valued Senior Member

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    Fascinating! Thank Fraggle! So then is that when electrolytes come in?
     
  12. Roman Banned Banned

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    Ionization is one way of having atoms meet their octet, where one atom loses at least one electron, and another gains at least one. Covalent bonding is another way of meeting octets, where the electrons hang around each atom equally. These are on a scale, it's not a binary system. So you can have slight ionic character in a mostly covalent bond. Electronegativity differences between the two elements are what decide if it's a covalent or ionic bond.

    Note that transfer of a single electron DOESN'T always result in an anion or cation (negatively or positively charged ion, respectively) but can instead result in a radical. Radical formation occurs when an element has an odd number of electrons around it, such as Chlorine with only 7 electrons, represented as Cl•.
     
  13. Bishadi Banned Banned

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    2,745

    they don't!


    Proof....... note any battery. Only the positive of THAT battery has a potential between that negative. Meaning the electron from one atom does not convey to another atom and cause a potential with another system.

    a potential difference is between the mass that is interacting

    Ionization is between the structures of the immediate system that share energy. i.e...... a conversation between people causes an ionization by the energy exchanged.

    THERE is no such thing as an electron that is not entangled to its source. Meaning you cannot take an electron from one atom and put in onto another without the initial 2 maintaining a potential between the 2.

    Reality in a nutshell! Check it yourself.
     
  14. Fraggle Rocker Staff Member

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    Yes. An electrolyte is a substance that contains free ions, i.e., atoms of two or more elements that once comprised a molecule of a chemical compound, but have separated, without returning the bonding electrons to their original incomplete orbits, thereby retaining electrical charges. The most common kind of electrolyte in everyday experience is a liquid containing the ions created by the molecules of another compound dissolving in it. But it's also possible for a solid to melt and for ions to exist within its molten state. It's even possible for ions to exist in a solid although I'm not enough of a chemist to explain that.
     
  15. MacGyver1968 Fixin' Shit that Ain't Broke Valued Senior Member

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    Isn't it though? I love learnin' me some new fancy science.

    Please Register or Log in to view the hidden image!

     
  16. Fraggle Rocker Staff Member

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    I'm not quite sure what principle you were expressing in your answer to this question, but the correct answer is that atoms really do gain and lose electrons. That is what ions are. An ion is an atom that has the wrong number of electrons.

    Sure, you could say that when two atoms combine to form a molecule of a compound, neither atom actually gains or loses an electron because their orbits are so close that they interlock. The electrons travel around in a complicated Heisenbergian pattern so that you can't say which electron is attached to which atom.

    But once the molecule ionizes, the two atoms move far enough apart that their orbits no longer interlock and every electron is associated with only one of the two atoms. One of them does indeed lose one or more electrons, which are carried away by the other one.
     
  17. Bishadi Banned Banned

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    2,745
    you mean a potential difference between mass.

    The 'electron' idea is a bohring description as any battery shares that if you take an 'electron' from one side, ONLY the 2 poles of that exchange have a potential difference.

    So then ONLY them 2 would have a potential between them but that is not what is observed is it?

    Ionization is like imposing a biased potential rather than an electric because the electric is bound to the initial system (note every electrical circuit).
     
  18. Trippy ALEA IACTA EST Staff Member

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    Wrong.
    The existence of Ions and free Radicals says otherwise. If you don't believe me, leave a some chloroform in a clear (and colourless) jar sitting in the sun for a few days, open it and inhale deeply - the thing that just killed you is free radicals.

    Wrong. That's not how batteries operate.
    Any chemical reaction involves the transfer of electrons. The difference between an Ionic bond and a covalent bond is one of degree.

    A battery uses this, typically, a battery uses some form of Redox reaction where the reducing agent, and the oxidizing agent are seperated. The two components are seperated by some physical barrier that allows the passage of ions to preserve charge balancing (this is called the electrolyte).

    In essence, the reducing agent sacrifices an electron.
    That electron is made to pass through a ciruit and do useful work.
    Once the electron has done useful work, it is absorbed by the oxidizing agent.
    This is why batteries only have finite charge, because there are only a finite mass of reactants.
    This is also why batteries loose their charge if stored for too long.
    Finally, this is also why some batteries are non-rechargeble, because some of the reactions are irreversable, and some of those that are reversable can lead to the production of dangerous substances (for example Hydrogen, which represents an explosion hazard).

    Without wanting to be rude, this is mostly gibberish, and makes little sense.

    It's also blatantly wrong - if it was true, your car wouldn't start, Lightning wouldn't occur, TV's wouldn't work, and neither would your national power grid.
     
  19. Trippy ALEA IACTA EST Staff Member

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    Many modern rechargeable batteries use solid electrolytes.

    This goes back to what I said in my first post, and partly involves what I said in my last post.
     
  20. Bishadi Banned Banned

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    2,745
    but you are still tapping keys

    please try it again


    and EVERY battery shares that ONLY the difference from its circuit can the system be used. For example if you were correct. i should be able to take the negative side from any battery and combine it with the positive of any battery (same voltage of course) and without putting them in series or parallel a circuit should be available but that is not how it works now does it.


    same with a power grid, the car, lightning and no matter how you wish to identify the system; the only way the energy conveys in an 'electron' ic system is within its own system and all other releases are electromagnetic or momentum


    problem is you actually believe an electron is an isolated unit of mass


    another bohr-ing error.....
     
  21. Trippy ALEA IACTA EST Staff Member

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    No.


    Well, no, here you're just misrepresenting what i've said. Nothing I have stated even remotely implies this, in fact, it implies quite the opposite, because if you take the time to understand what I actually wrote, you'd see that no current could flow in your nonsensical scenario, because there's no way for the reactants to react with each other.

    Elctrochemical cells, on the whole, form a balanced reaction, but, if as you've described in your nonsensensical scenario, you seperate the two parts of the reaction, well then nothing's going to happen is it?


    Wrong.


    Wrong again, I believe the emperical evidence which demonstates, unequivocally that an electron can be stripped from an atom, without being entangled to that atom, without some macgical special connection, and that entangling an electron to any other object requires a special, deliberate effort under special circumstances.
     
  22. Trippy ALEA IACTA EST Staff Member

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    10,890
    Take, for example, the good old fashioned Lead-acid battery.

    Second lowest energy to weight ratio.

    One 'cell' has two electrodes. A lead electrode (the Anode) and the lead dioxide electrode (Cathode).

    Over all, the reaction that's actually doing the work is this one.

    Pb + Pb(IV) -> 2Pb(II)

    Charge and mass is balanced.

    What the Lead acid battery does, is seperate this into two halves:

    Pb -> Pb(II) + 2e-
    Pb(IV) + 2e- -> Pb(II)

    Every time the reaction occurs, those electrons are forced to go through a circuit and do useful work.

    How a lead acid battery does accomplishes this 'amazing' feat is by using Sulfuric acid to mediate the charge balance in the battery. The Sulfuric acid is the electrolyte. In a lead acid battery, the Pb(IV) is provided by the lead dioxide.

    Including the Sulfuric acid in the equation we get:

    Pb + HSO4- + H2O <-> PbSO4 + H3O+ +2e-

    And

    PbO2 + 3H3O+ + HSO4- + 2e- <-> PbSO4 + 5H2O

    Over all, the reaction is:

    Pb + PbO2 + 2HSO4- + 2H3O+ <-> 2PbSO4 + 4H2O

    The astute among you will be able to see how the electrolyte provides mass balance, and charge balance, and will be able to intuit precisely why comments like "I should be able to take the negative side from any battery and combine it with the positive of any battery and without putting them in series or parallel a circuit should be available" should be disregarded as pure nonsense.
     
  23. Bishadi Banned Banned

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    2,745
    darn it, i thought you like to experiment like in science.


    gotcha!

    Are you suggesting that unless the potential is being used the procession cannot occur? Otherwise the model of a battery suggests the reactant is occurring and the electrons are piled to one side (ionized). such that one side is loaded with electrons and the other is left positive as if a vacuum to negativety (electrons). This would mean that any electron should fill the void and then any atoms missing an electron should be able to capture any free electron but you confirmed that unless the circuit is closed that this does not occur.

    Point is that an electron from a system remains within the system where the potential difference (ionization) occurs.

    Nothing to debate as all the electrical and 'electron' ic systems follow this same reality. Nothing really new but the observation of literal facts combined simply by awareness of more than one field of the sciences.

    Exactly! So now you just assisted the individual in understanding ionizations.

    Got to have two sides for the 'balanced reaction' of a potential difference using the per se 'electron.'




    Which empirical evidence.... when you just shared that without the circuit being closed the reaction cannot occur

    this is where your integrity is less than your knowledge and comprehension

    where is an electron in existence without a proton......... don't care which frame you work with ie.... what is the negative charge too?

    this is where to simply observe the logic and facts that you can expand your knowledge base.
     
    Last edited: Dec 4, 2008

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