To add comments or start new threads please go to the full version of: Electrons
PhysForum Science, Physics and Technology Discussion Forums > Biology, Chemistry, Medicine, Other Sciences > Chemistry

H2O
I've been thinking about how light travels through matter. More specifically I've been thinking about how electrons will increase in energy level upon absorbing a photon. Now I know that if the electron of an atom (or molecule) absorbs a high enough energy photon that the electron increase in energy level to a level where the nucleus no longer has a hold on it and it then becomes a radical. So with water it would be....(bare with me on this part tongue.gif )

H2O + photon -> H2O+ + e-

If this is true then would the following be true?

H2O + 2photon -> H2O+2 + 2e-

Now if that is true and keeping in mind that the HO bond is covalent (sharing 2 electrons) then would the following be true?

H2O + 4photon -> (2H+) + (O+2) + (4e-)

I put in the brackets to avoid confusion. I am also not sure if it should be O+2 or O2+. I put O+2 because O2+ could be a molecule of oxygen missing an electron.
rpenner
If the photon is energetic enough you can photo-disassociate the oxygen nucleus.

But I'm not convinced that H₂O⁺ is stable, especially in bulk water.
Kaeroll
I suspect it may be possible to form H2O(2+) in the gas phase, say during a MS experiment. But as rpenner correctly says, in solution it'd be highly unstable - possibly so unstable as to be undetectable.

Bear in mind that as you remove electrons from a molecule, each successive photon will be of higher energy. There are also other routes that can be taken if the right energy photon is used; I don't know about water, but - for example - H2O2 can easily homolyse to form two OH radicals.
H2O
I've been reading some e-books I got from a friend, one of which is "The Hydrogen Bond and the Water Molecule - Y. Marechal (Elsevier, 2007) WW.pdf". I have a hard time understanding some of it since I have no formal education beyond high school level (only self study) but it did state that a couple of eV (UV b or C) is all that is needed to bump out electrons from the outer shell. A couple of keV (x-ray of <1nm wavelength) is capable of removing inner shell electrons and then MeV (gamma rays) can knock out neutrons (and maybe protons) from the nucleus.

The last one surprised me. I knew that the nucleus can absorb photons but never knew nucleus particles could be knocked out because of them. I thought the strong nuclear force was too strong for that but I guess it is only in the MeV range.

So the reason for all this is to see if the separation of water into its elements can occur by the assist of photons.

From what I gathered so far, I'm looking to have 4 x-ray sources each putting out 1.3keV x-rays (for a total of 4.2keV) and have them pointing at each other. I may even utilize the z axis and use 6 sources (for 6.8keV). The idea is that I want to take advantage of the wave property of light and have the 4/6 sources converge to produce constructive wave interference upon a central location. This should remove the outer shell electrons outright leaving a very reactive "soup" of radicals. I predict that the the hydrogen nuclei would free up with no electrons and the remaining oxygen nuclei will have some electrons but would still be a positive ion.

Then there would be two plates connected to a power source such that one becomes and anode and the other a cathode. The hydrogen and oxygen nuclei would be attracted to the cathode while the electrons would travel to the anode. So with the water as water there is no current and as soon as the the x-rays begin stripping electrons a current should then develop.

The development of a current would be the proof of the ionization taking place as the voltage applied to the plates would be too small to actually produce a current through distilled water. The production of hydrogen and oxygen gas would be the proof that the degree of ionization I am trying to obtain is actually taking place.

It's not enough that the gas is produced. It must be produced on the cathode only. Then it is just a matter of igniting the gas mixture to make sure it is indeed hydrogen/oxygen gas.
H2O
What I know is that each shell is best described as a cloud layer. The electrons don't orbit the nucleus like planets orbiting the sun but instead they simply wizz around within the cloud layer. For an electron to go from one shell to another it must absorb a specific amount of energy. The factors that I know of that determine the amount of energy is at what shell is the electron starting from and to what shell the electron going to. I have no doubt there are more factors. For instance, once one electron is removed are the others held more tightly? Thus requiring more energy for the second to be removed?

If the electron absorbs only 50% or even 99% of the energy required to increase in energy level by one, it will not move. It takes a very specific quantity of energy to move an electron from one layer to another. I think that is the whole point behind the name quantumphysics.

From what I can tell is that there are many different ways to move the electrons/break the bonds. Thermal energy can do it, electromagnetic can do it, electricity can do it. You simply need to put the right amount of energy in joules to the bond.
H2O
If what your saying is that you thought the same photon gets emitted that got absorbed then nope. From my understanding it is the reason why things have color. Shine white light on something red and what you have is all the visible spectrum of photons bombarding the atoms and/or molecules of something red, being absorbed but only red photons are being emitted. Now in the case of say violet light that is high energy on something red, one violet photon will raise the electron so many energy levels but then the electron will release multiple red photons. It's still the same out as what went in just different.

Not sure how accurate that is, please feel free to correct me if I am mistaken.
H2O
If you mean that if an electron absorbed only have the energy required to go up an energy level, that it will move up halfway then no. If an electron only absorbs half the necessary energy to move up an energy level it simply will not move up at all.
H2O
Not sure where your getting the increase in mass from? Photons have no mass, that is their energy is in their momentum. Had to do some googling here but....

E = mc^2 is only a mass energy conversion of matter at rest where the full equation is....

E^2 = m^2 * c^4 + p^2 * c^2

If m = 0 then E^2 = p^2 * c^2 or E = pc

Since c is constant then p (momentum) is where the photons get their energy. p = h/λ where h is another constant then the momentum comes from the photon's wavelength. Thus the energy comes from the wavelength where the shorter the wavelength, the higher the energy.

Not sure but I do believe that the full E = mc^2 equation can apply to electrons. Where m = 0 for a photon, the m for the electron is not 0 and doesn't change so what you get is an increase in p. This increase in momentum is what determines what energy level the electron is in. It is near the limits of my current understanding but this website gives a good description of the relationship between an electron's momentum and energy level...

http://www.colorado.edu/physics/2000/quant...ne/balmer2.html
H2O
Google search for "electron mass" gave me 9.10938188e-31 kg. As far as I know this is the mass of an electron cut and dry, bound or unbound.
H2O
Not sure but I think it's kinetic. This would make sense if you considered the operation of a microwave. It uses electromagnetic radiation whose wavelength is longer than that of the visual spectrum meaning the photons involved have relatively low energy.
H2O
What velocities, what extra mass? Then explain a microwave oven...
H2O
Understand that heat is what you have when the molecules of a substance (or atoms when talking of substances like helium where the molecule is a single atom) is vibrating.

I see what you're saying though in that this vibration is still the molecules/atoms moving and since they have mass they can not obtain the speed of light. But that is not an indication of a limit to temperature. Take water for example. Cold it is a solid, it melts to become a liquid. Further heating makes it a gas. Further heating beyond that will actually break the bonds resulting in hydrogen and oxygen plasma. Further heating (I believe from articles I've read) can actually resulting in the nucleus coming apart leaving you with a soup of electrons, quark clusters and gluons moving about within the very high energy environment. Further heating allows the quark clusters to come apart so now you have a soup of up quarks, down quarks, gluons, and electrons. I can't remember if any of these particles are made up of smaller ones but if they were they would "come apart" if heated further.

Essentially what I did was reversed an article I read in a science magazine. It theorized the state of the universe at the time of the big bang and showed a picture of a time line. It illustrated the formation of the known particles at what time after the bang and the amount of energy in joules and the rough diameter of the spherical space occupied.

Here are two such illustrations.

http://www.crystalinks.com/bigbang2.jpg

http://satirica.net/wp-content/uploads/200...ng_universe.jpg

But all this is neither here nor there and highly irrelevant.
Guest
It is clear that Cusa knows nothing about chemistry. Ignore him.
PhysOrg scientific forums are totally dedicated to science, physics, and technology. Besides topical forums such as nanotechnology, quantum physics, silicon and III-V technology, applied physics, materials, space and others, you can also join our news and publications discussions. We also provide an off-topic forum category. If you need specific help on a scientific problem or have a question related to physics or technology, visit the PhysOrg Forums. Here you’ll find experts from various fields online every day.
To quit out of "lo-fi" mode and return to the regular forums, please click here.
©PhysOrg.com - physics and technology news - Version for PDAs