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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."
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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If it was dogma the priests of chemistry would be denying the evidence and punishing its discoverers.
Evidence you are not a scientist. The word "dogma" just has a different meaning from what you are used to when talking about science. To wit: "The Central Dogma". You should call up Francis Crick and tell him he was using that word wrong. Maybe they will posthumously take back his Nobel Prize.
Just callin' it like I see it.
Scientific theories only hold out until something else comes along with more facts that change our understanding
Right. That's called the scientific method.
It's kinda the whole point. Do what you can with what you have where you are, and when you find out how you're wrong you adapt.
Ice Cream has no bones.
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.
500+ years ago scientists thought the earth was flat.
No, they really didn't. Hell, over 2000 years ago the Greeks already knew the Earth was a sphere. They even knew its diameter! The idea that everyone ever thought the world was flat is entirely false - go ready a history book and stop perpetuating such garbage.
No need. Crick has already acknowledged that he really didn't understand the meaning of the word "dogma" when he used it. However, his ideas were so grond breaking that the word itself has changed/added meaning to accommodate him.
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.
No, they didn't. It's called the flat earth myth.
Uh, yeah? That's the whole point of Science. Scientists try to create theories that best fit the available data. More importantly, they are always looking for new evidence which will either corroborate or contradict their theories.
No, they failed because, as everyone knows, the center of the Earth is actually hollow, contains a breathable atmosphere, and is full of prehistoric creatures.
The higher the technology, the sharper that two-edged sword.
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!
It wasn't forgotten. The reason Columbus had so much trouble getting funding was that the royal courts of the time hadn't forgotten; they used Eratosthenes' old number (confirmed by the astrolabe), and then accepted Ptolemy's assessment that it was 180 degrees from one end of Europe to the opposite end of Asia. They knew there was no way that Columbus could reach Japan from the Canaries, 12,000 miles away, without running out of water (no ship of the era was big enough to carry enough for a trip of that length). So advised against giving him money, no matter how much Columbus insisted it was only 2,300. As it was, the reason why the terms of his contract with Fredinand & Isabella was so generous is that everyone expected him to die on the trip rather than make landfall.
And Columbus wasn't ignorant of Eratosthenes' number and Ptolemy's estimate; it was simply that he reached his error based on a different set of authorities:
1) That of Marinus of Tyre (from the first century AD), who thought that Eurasia was 235 degrees in width instead of about 180.
2) The measurement of Alfraganus that underestimated the size of a degree somewhat.
3) His own mistake of assuming that Alfraganus's mile was the same length as an Italian mile (which were 2/3rd the size).
Based on those numbers, it was perfectly reasonable to believe he'd reached Asia.
Oh dear... as someone said already, I expect this is probably an electric universe rant, and that responding to it will do almost nothing. I could moderate it down, but other mods probably wouldn't understand my reasons for doing so, as the parent avoided mentioning the crackpot theory itself.
It should be said, however, that the odd thing about the dark matter predictions are that they work very well, as do the dark energy predictions. We did many have other models that were put forward, some containing significant changes to various theories. None of them worked nearly as well as our current model with dark matter. There are many people in the community that don't like our lack of knowledge about dark matter, but it works so well that, as with many things in high energy physics, we can only assume that it is actually there until we come up with a better theory.
As for black holes, I would suggest that you actually learn modern GR before suggesting that you understand the theory better than everyone else in the community does. In fact, try learning real cosmology, and looking at results like measurements of CMB anisotropy, and Big Bang nucleosynthesis.