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New Results Contradict Long-Held Chemistry Dogma
An anonymous reader writes "Researchers have found that the long-held belief that only the outer, valence, electrons of an atom interact may be false. Computer simulations have shown that at pressures like those in the center of the Earth the inner, core, electrons of lithium also interact."
Dogma?
If it was dogma the priests of chemistry would be denying the evidence and punishing its discoverers.
That's the difference between science and religion. For science, new information enlarges our understanding of the world. For religion, new information only threatens sanctified prejudices.
Proud member of the Weirdo-American community.
For anyone who wants to read the actual paper: http://arxiv.org/abs/0805.2781
"It take 9 months to bear a child, no matter how many women you assign to the job."
Just because an electron is in the outer "core" doesn't mean it's a valence electron. Similarly, the converse is also true. As IUPAC put it, the number of valence electrons is equal to "the maximum number of univalent atoms (originally hydrogen or chlorine atoms) that may combine with an atom of the element under consideration, or with a fragment, or for which an atom of this element can be substituted." This still holds true for the interactions in question in TFA.
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Aahhh, that's why all the experiments I made while standing in the center of the earth sometime failed!
Now that's a fucking shocker. Most Chemistry today focuses on conditions either similar to STP or than can be created within STP. STP is "Standard Temperature and Pressure" Usually defined for the purpose of convenience of communication as 298K and 760 Torr. They define this as "standard" because everybody in Chemistry knows that chemistry changes as you change conditions, and it's useful to have a standard to compare to, even an arbitrary one (298K, 760 Torr is "average" sea level temperature and air pressure). The standard is also very useful for Chemical Engineering.
The article is poorly written garbage.
High-pressure reactions are an almost completely unexplored aspect of chemistry; and the research that has been done shows that atoms and molecules behave much differently under high pressures. For example, a lot of research is being done now utilizing ultra-high pressure water as a replacement for organic solvents, for greener chemistry. If there's one thing we've learned from these high-pressure experiments, it's that everything acts different, so it really doesn't go against our "dogma" at all; it just goes against the "dogma" of STP reactions, which makes sense, as this was not an STP reaction. It's an incredibly cool finding; just not something that's going to turn all of our current chemical understanding upside down by violating "dogma."
My sister opened a computer store in Hawaii. She sells C shells by the seashore.
Chemists already know that core electrons do influence bonding and such. It is simply a short cut to ignore them. Hence, when one wants to get the last few digits on your answer you turn on "core correlation" which treats the core and valance regions the same.
Furthermore, the conditions in question here are so extreme as to border on being a plasma or some such. So I am not really surprised to see some effect that are negligible under "normal" conditions to grow and become important.
Computer simulations?
You mean like the computer simulations that say the earth is warming? Hahahaha...
Indeed. Between your intuition and computer simulations running on super-computers based on decades of research on predictive models designed by the most competent and dedicated researchers in the domain, always trust your intuition.
This is why I never watch the weather channel, I just look at how leaves move in the wind, how menacing clouds look, then I wet my pointer finger, put it in the air and I can tell you how the weather will be tomorrow. Well I can tell what it will be, doesn't mean I turn out to be right, but hey, the Weather Channel is wrong sometimes too!
You just got troll'd!
was any 'dogma' really overturned? My understanding was always that the basic chemical rules were first order approximations, not a comprehensive description of how everything must behave. For example, xenon is an 'inert' element, with the outer shell full, but xenon tetra-fluoride (XeF4) is a stable compound. I learned that in high-school in the 1980's.
For supposedly trying to be neutral, a lot more posts negative of religion or the right get modded up.
Who promised you "neutrality"? Good posts that are negative of religion or the right are just easier to write. You see more of them modded up because more of them are posted.
Instead of whining that everyone is biased, why don't you just mod up posts you agree with if you don't like it, or start writing posts "positive of religion or the right" that are actually insightful or interesting?
Chemistry's rules exist because they functionally explain chemistry in an accessible manner. Physicists have known that there are more accurate models for a while. Unfortunately, these models are too complex to be useful to someone trying to synthesize a chemical. If this has any significant applications, we will still be seeing classical chemistry for at least a century to come (barring the singularity.)
I mean, it's been almost a century since relativity and quantum mechanics came on the scene, but for the majority of engineering tasks, they remain useless. Between processors hitting the atomic scale and more probes hitting the atmosphere, that may change. However, I don't see chemistry getting to the point where we even begin to see practical chemistry that doesn't rely on classical models. The new ones are simply to complex to use.
IAAC (I am a chemist)
Honestly this result is not unexpected. The interactions of electrons and nuclei depend on several factors: distance, energy, and charge. There is also the factor of election-electron interaction, which is where the idea of valence electrons comes about.
Normally the outermost electrons of an atom are far enough from the nucleus that the distance from the nucleus and the repulsion from the other electrons on the atom allows them to more easily interact with other atoms. This is how bonding works, an electron gets "shared" between two atoms or the electron completely jumps off the atom and turns the atom into an ion which is attracted to other, oppositely charged, ions. Yes, I'm oversimplifying quite a bit for the layman.
Every electron in an atom can interact with another atom, it's just MUCH less likely to happen for the inner electrons of an atom and the interactions of the inner electrons to other atoms are much weaker than those of the outer electrons. Increasing the pressure allows the inner electrons to interact more strongly with other atoms.
Under higher pressures and energies two things happen. First of all atoms are pressed closer to each other. This means that all of the electrons are closer to other atoms. This increases the likelihood that an electron will interact with another atom, forming a bond. The second effect is that the increased energy tends to cause the electrons in atoms to jump to higher energy states which are further out from that atom's nucleus. This means less crowding which means less repulsion from other electrons which means that each atom's nucleus is more exposed to interaction with other atom's electrons. Again, I'm oversimplifying for the layman.
The extreme of this is when the pressure is great enough that each nucleus gets close enough for the nuclear force to overcome the electrostatic repelling force between the two positively charged nuclei. When this happens you get neutronium, the core of a neutron star. Obviously you don't normally see these levels of pressure on Earth!
What is really in question is the exact numbers of the interactions. At what pressure does a certain phase of atom to atom interaction appear? How does the increased pressure affect rates of reactions between atoms? Scientists are trying to measure hard numbers of the effects of pressure on chemistry. There already is a good deal of theoretical work but the experimental work is a bit tough to do given the conditions needed.
Sapere aude!
For instance, you can scientifically prove that God doesn't exist all you want given the small amount of information we know about our universe.
well, we know where you get your bias against science.
Science tries to prove testable positives. You know a theory is "wrong" if the observations don't match the hypothesis. Even then, it doesn't necessarily mean the theory must be completely disregarded (example: newtonian and quantum mechanics coexist today).
You can't "disprove" god with science because god is not rationally testable. You can't "prove" it either because of that, though, and as such no man of science will accept "the will of god" as an explanation for something, or a reason to perform/avoid certain actions.
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No, you cannot. Its impossible to show scientifically that anything doesn't exit. You can just show that something actually does exist. Thats why we were able to prove that, under condition XYZ, only valance electrons react. As long as we didn't test it in every possible scenario (and even then, we cannot prove that there aren't any other possibility), we cannot say that there aren't some ways where that theory doesn't hold. And as this showed, there was a scenario we hadn't tested.
Scientists (real ones) will never say that its impossible for God to exist. They'll just say that all of the currently provided evidence are bogus, and that there isn't any valid theory that shows its existance beyond wishful thinking by a few zealots. Doesn't change that God may exist. We just have nothing to lead us to think it does.
If some scientist claims to be able to prove that it doesn't exist (or that ANYTHING ELSE doesn't exist), they're doing faux-science.