Talk:Ion
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[edit] Detached information
The following has been removed from the article. It is not very clear, so at the very least it doesn't belong in the intro and I don't know where to put it, and it likely ought to be rewritten.
- The formation of free negatively charged atomic ions is non-trivial because an additional electron doesn't experience a Coulomb attraction towards the neutral atom. It is nevertheless possible in many cases, see negative atomic ion.
- In larger systems ions are often formed by the combination of elemental ions such as H+ with neutral molecules or by the loss of such elemental ions. The distinction between this and the removal of an electron from the whole molecule is important in large systems because it usually results in much more stable ions with complete electron shells. A good simple example of this is the ammonium ion NH4+ which has the same number of electrons as NH3 in essentially the same configuration. The charge has been added by the addition of a proton (H+) not the addition or removal of electrons.
- Centrx 21:36, 9 August 2005 (UTC)
Reworked the second paragraph here and made it into a new section on formation of polyatomic and molecular ions. —The preceding unsigned comment was added by 134.9.228.11 (talk • contribs) 21:29, 1 March 2006.
[edit] Negative ions / health benefits?
A lot of "ionizers" claim to produce negative ions, which can make you happier and wealthier. What's the scientific basis for this (if any)? ---Ransom
Ransom I believe that the "negatively charged ions" referred to here are a small number of charged air molecules (or more likely dust particles) generated by passing the air flow over a discharge point within the "ioniser". The number produced are quite small, the analogy is the charge you can get on a plastic object rubbed on silk or rayon. Not really anything to do with ions in the chemical sense. JohnT 13:12, 28 December 2005 (UTC)
[edit] Beware the "Healthful Negative ions" pseudo-science scams: the folks who sell them don't even know what ions are.
Ransom, there is no scientific basis for any of that. That kind of marketing is pseudoscience that attempts to market to people who don't know any better but to "trust the scientists" (or rather, the person blabing on with scientific sounding terms).
If you ionize the air, the only thing that happens is that the ionized molecules and particles that have picked up a charge seek to neutralize themselves by sticking to things of the opposite charge, wherever they may be. For example, dust particles that usually have a positive charge (the reason for they tend to be positive has to do with the way common dust particles pick up static charges--it's beyond the scope of my explanation) end up sticking to TV screens, since old cathod ray tube TV screens pick up a negative charge from all the electrons that bombard it to produce the image on the surface. Charged things tend to try to seek out opposite charges to become neutral.
What's worse is that running air through something that ionizes it may actually make any present toxic chemicals more dangerous to you. There used to be a major scare that high voltage power transmission lines caused cancer because of the strong electric field around them, or their low frequency electromagnetic radiation. Then, someone took a closer look at the geographic distribution of the cancers, and found that they were concentrated down wind of the polution and the high voltage lines. If I remember correctly, what they think was going on was that the polutants were being charged by being blown through high voltage wires, and once charged, were "sticky", and stuck to anything they could that would help neutralize their charge--including human lungs. Ionizing the air made the present polutants *more* deadly, not less.
The only ionizing product that does the air any good is an ionizing air filter. (Most famously, the heavily advertised "ionic breeze" device by Sharper Image) Filters of that sort don't just ionize the air: they ionize the air with one charge, then run the air past plates of the oposite charge, so the charged dust and contaminants get pulled out of the air by their attraction to the oppositly charged collection plates. Unlike the open air high voltage wires, these didn't just leave the polutants "sticky" with charge, they also provide oppositely charged plates for the sticky polutants to collect on, thereby filtering the air.
The worst offender by means of "healthful negative ion" pseudoscience scams are those "himalayan salt crystal lamps" that allegedly fill the air with negative ions. They do no such thing. The people who market those things just prove that they didn't learn a thing in High school science classes (or if they did, they learned that you can market things to the new-age "holistic health" crowd using scientific terms, and fool most people into buying anything). Indeed, they can't even tell you what ions the things are supposedly releasing into the air, much less what an ion is or what ionization means.) Nothing but radioactive material undergoing alpha decay continuously releases ions into the air. No salt crystal can release negative ions into the air without becoming extremely positively charged, and nothing naturally and continuously leaves electrical equilibrium (charge neutrality) on its own. The salt crystal lamps certainly don't. All you get with one of those lamps is a block of dimly lit expensive salt.
Mined rock salt crystals are by far dominanty sodium choride (as in 98% or more), with trace amounts of other positive and negative ion combinations (potassium/calcum/magnesium etc. chloride/flouride/bromide/iodide etc. see the halides wikipedia entry). If a salt crystal were to give off negative ions, you'd have the air filled with ionized halogens. That would be extremely bad for your health if that were so! Imagine the air filled with chorine ions (the domiant negative ion in crystal salt). That would kill you or make you ill if it actually did such a thing; chlorine gas is toxic as is and was used as a chemical weapon in WWI, forget about even ionized chorine!
Berkana 10:05, 24 February 2006 (UTC)
- There seem to be different types of air ionizers and different theories of how they work. Someone who knows should really update the article. The only undisputed facts I can gather are:
- The devices involve high voltages
- They create ozone and nitrogen oxides, which kill bacteria, but are also toxic to people. Whether this is a side effect or the intended effect is disputed.
- Unanswered questions:
- Does the device "purify" the air in other ways, like removing dust and bacteria from it?
- Does the device involve two oppositely-charged electrodes or only one electrode that is at a high voltage relative to the Earth?
- Are the dust particles attracted to the other electrode (how does it stay clean?) or are they charged and then attracted to other neutral objects in the room? (I've heard rumors of stains on the walls near these machines.)
- If the device is emitting ions into the room, which are then attracted to the Earth (or other objects in the room), are they positive or negative ions? Can it emit both at the same time? (Do ions in a neutral fluid rapidly move towards oppositely charged objects and neutralize, or are they slowed down by the collisions with neutral particles and only slowly drift towards other objects? Would a positive and negative ion neutralize on contact, or does it depend on other factors?)
- It's actually more complex than it seems, and only physicists or chemists who really understand ionization and electrohydrodynamics really know what's going on. (And I am not one of them, obviously.) — Omegatron 17:13, 24 February 2006 (UTC)
No salt crystal can release negative ions into the air without becoming extremely positively charged
- If you put it in water, it will constantly emit both positive and negative ions, no?
- If you put it in air instead, won't part of it evaporate? What form are the evaporated atoms/molecules? — Omegatron 17:29, 24 February 2006 (UTC)
The only ionizing product that does the air any good is an ionizing air filter. (Most famously, the heavily advertised "ionic breeze" device by Sharper Image)
- You mean an electrostatic precipitator, I believe. And I don't think the Ionic Breeze works as one. I could be wrong. — Omegatron 16:58, 27 October 2006 (UTC)
[edit] ionzation energy and its effect on chemical reactions
ionization energy is the energy needed to essentially remove an electron, i was curious to know what would happen if an element was stripped of its electrons, so as to resemble the valance electron configuration of another elemnt. would it have the same chemical properties as the new valance configuration? --Shinjiro 01:53, 4 March 2006 (UTC)
[edit] Ion tables
I converted the lists of ions into tables (full description in edit history) but it's 3:45 in the morning where I am, so I need someone to make sure all the charges/subscripts are correct. Thanks.—Kbolino 08:48, 24 March 2006 (UTC). .
