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-   -   atom to have no electrons? (http://www.physicsforums.com/showthread.php?t=50333)

Gary King Oct29-04 05:56 PM

atom to have no electrons?
 
is it possible for an atom to have no electrons?

movies Oct29-04 06:41 PM

Sure. This can be done quite easily in the gas phase. In solutions cationic species will be solvated by other molecules, but can be thought of as essentially "electronless."

vsage Oct29-04 08:17 PM

The easiest example to give are the Hydrogen ions that give acidity to a solution. Those [tex]H^+[/tex] atoms are just nuclei.

ZapperZ Oct29-04 09:23 PM

Or consider the alpha particles, as in radiation particles. These are nothing more than bare helium nuclei.

Zz.

chem_tr Oct29-04 09:33 PM

ZapperZ, I am doubtful about this. When you write the alpha particle, [itex]^{4}_{2}He[/itex], you'll see that two electrons are present as this compound is neutral and monoatomic. You'd be correct if this compound were a 2+ ion. Or is there something I don't know?

vsage Oct29-04 10:04 PM

Quote:

Quote by chem_tr
ZapperZ, I am doubtful about this. When you write the alpha particle, [itex]^{4}_{2}He[/itex], you'll see that two electrons are present as this compound is neutral and monoatomic. You'd be correct if this compound were a 2+ ion. Or is there something I don't know?

Didn't rutherford use alpha particles in his gold foil experiment? I don't know if having electrons would have changed his result but I guess I always assumed that The alpha particles deflected off the nuclei of the atoms of the gold because they had a +2e charge. It's been over a year since I touched chemistry though and even then it was only first or second semester general chemistry so there's an exceedingly high probability I don't know what I'm talking about :).

altered-gravity Oct30-04 04:32 AM

Quote:

Quote by chem_tr
ZapperZ, I am doubtful about this. When you write the alpha particle, [itex]^{4}_{2}He[/itex], you'll see that two electrons are present as this compound is neutral and monoatomic. You'd be correct if this compound were a 2+ ion. Or is there something I don't know?

ALpha particles are charged, they can be denoted by [itex]^{4}_{2}He^{2+}[/itex] or just [itex]^{4}_{2}\alpha[/itex]. They are generated in the following reaction type:
[itex]^{a}_{b}X --> ^{4}_{2}\alpha+^{a-4}_{b-2}Y[/itex]

They are highly ionisating radiation, and can be defelcted in magnetic fields or accelerated in electric fields.

chem_tr Oct30-04 06:46 AM

Thank you for this valuable information. One small tip (not important at all), use \longrightarrow in the LaTeX image to obtain [itex]^{a}_{b}X \longrightarrow ^{4}_{2}\alpha+^{a-4}_{b-2}Y[/itex]

We understand that only small atoms can give all of their electrons; bigger atoms may be persuaded to give most of their electrons to yield unusual charges via core (nuclear) reactions, I think.

altered-gravity Oct30-04 07:11 AM

Quote:

Quote by chem_tr
\longrightarrow

Thanks! I was trying to find that..

Quote:

Quote by chem_tr
We understand that only small atoms can give all of their electrons; bigger atoms may be persuaded to give most of their electrons to yield unusual charges via core (nuclear) reactions, I think.

Yes, I suppose that itīs difficult to take out the "last" electrons of a big atom due to the high Z value (that causes very low energy values of the first atomic orbitals)

ZapperZ Oct30-04 07:17 AM

Quote:

Quote by chem_tr
ZapperZ, I am doubtful about this. When you write the alpha particle, [itex]^{4}_{2}He[/itex], you'll see that two electrons are present as this compound is neutral and monoatomic. You'd be correct if this compound were a 2+ ion. Or is there something I don't know?

http://scienceworld.wolfram.com/phys...aParticle.html

I'm also a certified Radiological Worker 1(OSHA category here in the US) since I work in a radiation controlled area. All the radiation safety training standards have defined "alpha radiation" as the doubly-ionized He.

Zz.

chem_tr Oct30-04 08:38 AM

Okay, thank you for the information. I didn't know that alpha particle is doubly ionized. So it is different from ordinary helium gas, our high-school-level chemistry courses state that alpha particle is the same as helium, and this doesn't seem to be correct.

selfAdjoint Oct30-04 08:53 AM

The alpha particle is a helium NUCLEUS, not a helium atom.

mrjeffy321 Oct30-04 01:00 PM

An Atom is: as defined from dictionary.com:
Quote:

"A unit of matter, the smallest unit of an element, having all the characteristics of that element and consisting of a dense, central, positively charged nucleus surrounded by a system of electrons. The entire structure has an approximate diameter of 10-8 centimeter and characteristically remains undivided in chemical reactions except for limited removal, transfer, or exchange of certain electrons."
so, in my opinion, No, it is not possible for an atom to have no elections becuase first of all it wouldnt be uncharged (which although is not included in the defintion above, needs to be true, other wise it is an ion), and second of all, it wouldnt share all the same characteristics of the element it should belong to, for example, the alpha particle above you all were talking about will not share the same properties as a helium atom will.

altered-gravity Oct30-04 02:40 PM

Quote:

Quote by mrjeffy321
first of all it wouldnt be uncharged (which although is not included in the defintion above, needs to be true, other wise it is an ion),

Of course. Thatīs the correct way of calling it. Nobody doubts that an ion is a completely different system than the neutral species, and that an hellium nucleus is NOT an helium atom.

mrjeffy321 Oct30-04 03:21 PM

well the question was whether it was possible for an atom to have no electrons, not whether protons (and possible neutrons) could exist without electrons.

ZapperZ Oct30-04 03:25 PM

Quote:

Quote by mrjeffy321
well the question was whether it was possible for an atom to have no electrons, not whether protons (and possible neutrons) could exist without electrons.

An atom without electrons IS just a lump of protons and neutrons! When you strip away all the electrons, you are left with just the nucleus. You were given two specific examples already.

Zz.

chem_tr Oct31-04 01:46 AM

ZapperZ is right, but only few examples can be mentioned about this. The most famous one is hydrogen ion, [itex]\displaystyle H^+[/itex] and the other is alpha particle, [itex]\displaystyle ^{4}_{2}He^{2+}[/itex].

However, there are not many; the other alternatives are so unstable that we can conclude these two are the only easily available. Please consider [itex]\displaystyle Li^{3+},Be^{4+},B^{5+}[/itex]. Very high amounts of energy have to be given to provide these unusual oxidation states.

Chronos Oct31-04 02:57 AM

Simple definitions might work here. The number of electrons surrounding the nucleus determine whether or not an atom is electrically charged or neutral. If an atom contains equal numbers of protons and electrons, it is described as being electrically neutral [and elemental]. If it has an unequal number of protons and electrons, it is an ion. An atom totally stripped of electrons is, technically speaking, a positively charged ion.


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