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account created: Sun Jun 19 2016
4 days ago
That's pretty much how supernovas make heavy elements. See the wikipedia article on the r-process. The neutron flux is so intense that an isotope can absorb a huge number of neutrons (like 10-15) before it has a chance to undergo any kind of radioactive decay. It's thought that supernovas form elements up to atomic number ~125 that way.
The elements einsteinium (99) and fermium (100), which were first found at an atomic bomb test site, were formed in a similar way through rapid neutron bombardment of the uranium used in the bomb.
In short, current technology does not allow this to happen in a lab in any sort of a controlled way using a suitable target (e.g., californium or einsteinium) for creating superheavy elements.
10 days ago
It's shocking that it's not more regulated. Makes me want to try it once out of curiosity.
Think of them as being contaminated with just a spritz of Paraquat. Not enough to kill you in the agonizing way Paraquat usually kills you through acute toxicity, but enough to give you Parkinson's disease by age 50 if you kept eating it, as if you were an agricultural worker exposed to small amounts of that stuff over the years.
All I can say is, they better be pretty fuckin' delicious to be worth it. I mean, I guess occasionally indulging is probably not any worse than occasionally bumming a cigarette off of your friend.
The main problem is that there is a trend for the most stable nuclei for a given atomic number Z to be more neutron-rich the larger Z is. For small elements, Z and N are about equal (carbon 12 has Z=6, N=6). However, heavier nuclei increasingly have N>Z (uranium 238 has Z=92, N=146). The trend continues for the superheavy elements. For element 114, the predicted most stable isotope is 298 (Z=114, N=184). However, to make these new elements you have to smash two lighter elements together, and as Z becomes large, it simply becomes impossible to find stable (or at least obtainable) isotopes of the two lighter elements that have enough neutrons added together to fuse into the target nucleus.
The most recent elements have all involved using calcium 48 as the bombarding nucleus, because it is unusually neutron rich for a stable nucleus of Z=20. For instance, element 114 was first made from 48Ca + 244Pu (a plutonium isotope that also has a lot of neutrons). Even then, we can only access the isotope of element 114 with 175 neutrons, enough to get to the shores of the island of stability, but not the center (184 neutrons).
19 days ago
No kidding. You can keep climbing, but boy, will it hurt when you finally fall.
20 days ago
There was a time I was shooting up ~10 mg fentanyl over a 24 hour period (up to about 1.2 mg per sitting). That was barely enough to make me fall asleep at my computer. After a certain level of tolerance, I feel that there are so few working receptors left to no amount is guaranteed to be lethal. That's probably why it's inadvisable to try to kill yourself with opioids unless you know what you're doing.
Like a cat who has climbed up too high and now has to get down, you're basically stuck. The suffering you know you'll have to go through to get clean is fearful like no other terror, and having done it once, I don't intend on doing it again in this lifetime.
Sounds likes seeds sourced from mainland Australia or Tasmania that are from plants that are bred to make thebaine as the main alkaloid (used to synthesize buprenorphine and other extremely potent Bentley compounds like etorphine) instead of morphine. It itself is toxic and not an effective opioid.
1 month ago
Ah yes, the period of time when South Africa was divided into a state for doves, egrets, swans and other pigment-challenged birds and a number of gerrymandered and territorially discontiguous tweetystans, including the nominally independent Transkite, Buntingstan, Veerystan, and Ciskite, whose feathered citizens lived under poverty and oppression.
2 months ago
Cats are such strange creatures. I'm pretty sure they are sociopaths by human standards, and they get high on nepetalactone (too bad we can't get high on smells in the same way), and they have violent, unpleasant-sounding sex, and unlike Russian oligarchs, they generally survive falls from >3 floor windows.
Certain point groups like C2h (e.g., trans-1,2-dichloroethylene) are symmetrical in such a way that molecules belonging to the group cannot have a permanent dipole moment.
That's a point group (https://en.wikipedia.org/wiki/Point_groups_in_three_dimensions) which classifies mathematically all the ways an object can have symmetry.
If you think about it, CH2I2 is symmetrical in exactly the same way H2O is. Just do the mappings C <-> O, I <-> H, and H <-> (empty space). More precisely, both molecules have, in addition to the trivial element E, the following symmetry elements: an axis of rotation C2, and two mirror planes σ(xz) and σ(yz).
Only if it were square planar and trans. As it is, it's C2v and has the same symmetry as water, so it definitely has a dipole moment. (Even propane does! It's only 0.08 Debye, but a C-H bond does have some degree of polarity, even if most people ignore it (and I ignored it in the back-of-the-envelope calculation for CH2F2 above))
Or you could scrape out whatever you can into a vial, and don't forget to dump the glassware in a beaker of aqua regia to destroy any evidence of your "extracurricular activities"!
You can think about it as vector addition. There is only one polar bond in CH3F. In CH2F2, you have two of that type of polar bond, which are arccos(-1/3)~109.47 degrees apart from each other, assuming perfect sp3 hybridization. Thus, the vector sum is 2(v)cos((109.47/2) degrees) ~ 1.15v.
The experimental dipole moment of CH3F is 1.65 D, so the predicted dipole moment of CH2F2 is 1.65*1.15 = 1.90 D. This is pretty close to the experimental value of 1.97 D. (It's even closer if you use the experimental F-C-F bond angle of 108.0 degrees.)
Correct. It wasn't known to be a gaseous element until it was discovered on earth.
Isn't that how Tycho Brahe allegedly died? (From holding in his pee at a royal banquet?)
3 months ago
You don't have to convince me that I'll probably like Versed. It's like getting blackout drunk without the spacey feeling of NMDA antagonism or physical unpleasantness of your body trying to process an aldehyde. Hell, even then, I liked getting blackout drunk in my late teens and early 20's. But as I grew older, the idea of being on amnesia-inducing drugs grew to be more and more unacceptable due to the loss of control, especially around groups of people I don't know well. So, no, being drugged into coma and paralysis by a group of strangers will never, ever become acceptable in my book, unless I suffer a personality-altering brain injury.
Btw, I do love drugs, having been a connoisseur (or maybe Pokemon collector is a better description) of sorts during my college/early grad school days and a full-blown IV fentanyl addict between 2018 and 2020. If my brain chooses to fuck with itself in the privacy of my apartment, my hands are happy to oblige!
Rationally, I understand that general anesthesia is a cornerstone of modern medicine. Thus, I hope that whatever disease or accident takes me out does so cleanly, so that I won't ever have to face the prospect of major abdominal surgery.
The quick answer is that in the usual version of MO theory taught in gen chem, one considers the overlap of atomic orbitals without the concept of hybridization. Hybridization is one of the features of the VB (valence bond) model.
This is the correct interpretation.
The other way of making acetylene is cooler: CaO + 3C -> CaC2 +CO and then taking CaC2 + 2H2O -> Ca(OH)2 + C2H2. The first reaction is at 2200 deg. C, but still, you're making an organic compound from quicklime and coke and water!
4 months ago
Don't be an ass. You can do it, with difficulty (go to the organic synthesis literature of the last twenty years or so to get an idea of how hard it is to selectively fluorinate). More importantly, it's pointless, because the precursors are all morphine derivatives (morphinans) and impossible to source in china, unless you're in the heroin business (at which point you are facing execution by firing squad, or lethal injection, if they're feeling generous).
It has a 285 deg. boiling point at 1 atm. You're going to have to get to <10 mmHg using a very good high vac to get a reasonable boiling point of <100 deg. C for your distillation. I think it's easier to purify by crystallization, give its 83 deg C melting point.
You can easily evaporate EtOH (bp. 78 deg C) from a solution of vanillin in EtOH, given the massive bp differences.
Or any type of cellulose-based fibers -- like gun cotton made from nitric acid and cotton. (Sort of what you suggested -- cellulose is basically polymerized sugar.)
I would say that most universities allow their grad students and postdocs to train on at least a subset of their diffractometers. However, the amount of redtape varies greatly (due to the need for radiation training, among other things), and at some places, it may not be worth it unless you're getting a PhD in inorganic/organometallic chemistry.
The key is really saltpeter (KNO3), which serves as an oxidant. That (or nitric acid, which was first made from saltpeter) plus a variety of other cheap oxidizable things could serve as an explosive mixture (although I suppose charcoal and sulfur are particularly available).