Kaeroll

Quite possibly. I'd not seen any posts by this chap before, so I figured I'd treat it as 'speculation' rather than pseudoscience.

Is there an 'entry requirement' for the politics forum? Can't post in there for some reason, and a quick search didn't turn up anything about it..

I'm not disagreeing that electron configuration determines reactivity - that much is clear to anyone. My main question is how your table is an improvement upon the current periodic table.

Lithium aluminium hydride. In addition to being a sure-fire way to liven up any synthesis, it's the slut of reducing agents - it goes all the way every time!

Whoops. This is what happens when I post before my morning coffee - I get it all wrong. Ignore my above post.

Off the top of my head, the Al cation is smaller and more charged than the Mg cation, i.e. greater charge density. Therefore in bonding to O, Al has a greater lattice enthalpy, which manifests as a high melting point. (whoops, got this wrong. Was half asleep when I posted. Ignore)

The methyl group is more or less neutral with regard to electron donation/withdrawal. As such the first subsitution is likely to occur at the para position for steric reasons. Beyond this you must consider the effect of the highly electron withdrawing nitro group on the mechanism of the reaction. (If you're not convinced it's electron withdrawing, try delocalising a negative charge into it using 'curly arrows' from the para position). Try pushing some charges round the ring and see which positions have the most electron density (i.e. no partial positive charge). This should tell you why you get the 1,3,5- compound. Bonus points: at room temperature, what product would you predict? Why? To get the tri-nitro compound you need relatively high temperatures and long reaction times, as the electron withdrawing nitro group deactivates the ring to electrophilic attack.

I believe it is. Not got my notes on this to hand but I don't recall any rules about symmetry operations bisecting atoms being forbidden.

To be blunt - take a course on enzyme chemistry, preferably as given by a chemist. In the 2nd/3rd/4th years of my undergraduate chemistry degree, modules on the 'organic chemistry approach' to metabolism and enzyme chemistry were given, and answer - to some extent - your question. If this isn't an option, go to a university library and get out a decent biochemistry text. I find Berg to be thorough yet accessible. Kaeroll

The two ends of a DNA strand are different to one another due to the structure of the phosphate-ribose backbone. The terms 5' and 3' (five-prime and three-prime) refer to the carbon atoms in the ribose; each monomer is attached to the next at these two positions. (Aside: why prime? Why not just 5 to 3? The plain numbers are used to designate carbons in the bases.) DNA is synthesised from the 5' end to the 3' end by DNA polymerase (I think- though the actual enzyme name is irrelevant to this discussion). As such it is conventional to list bases in the 5' to 3' direction, as a form of shorthand. If you've ever studied protein structure this is really quite similar to the N-C convention. Kaeroll

So your basic point is that because it's not immediately intuitive, or requires study, it's wrong? (Also - I've never quite got this 'Einstein said this therefore it's true' malarky. He also dismissed quantum mechanics...)

What data do you have available?

Whatever the basis of this - what is the point? It doesn't seem to demonstrate any useful relationships between elements as the traditional Table does. Also, while I am not familiar with the 'Casimir force' I also question the conclusion very strongly, as the existence of ions and of isoelectronic species with differing behaviour (amongst many other things) tell us that the proton number determines the element, not electron number.

It'll likely be lower. You're not really going to have much luck mixing chloroform and water in any case (hence its use as an extractant)

Corrected: pH = -log10[H+] I'm not quite sure what the OP is asking?

The theoretical limit of infinity comes up here and there in definitions. e.g. plots of potential energy between particles being measured from infinite separation. It is, as hermanntrude said, simply an extrapolation from values that we can measure.

I know when I was taught this in the first year as an ug, I was given a vague "lower energy". Great for the most part, but not so clear once you reach the d block. Kaeroll

Fair enough - I guess I've always used the n+l rule under the wrong name! Cheers for the clarification. Kaeroll

Hi, Realise this is a slight bump, but... Is this not the same as the Aufbau principle? If so it's in most modern books. Kaeroll

It's also worth adding that hydrogen bonds have a length which may or may not be greater than dispersion forces (I'm not sure off the top of my head). This is one reason ice is less dense than water, due to the lengths of the hydrogen bonds. Perhaps this is also a contributing factor? Kaeroll

I saw Tinselworm when he toured it round the UK. Didn't know he'd played Wembley though - impressive! As it happens I also got the compilation recently (after much borrowing of friends' dvds) Kaeroll

I'm surprised this hasn't come up yet... Dr Heisenberg is driving along the motorway when he sees the flash of a police car behind him. He pulls over, and up strolls the officer, fingers looped into his belt. "Well, well, well, sonny-Jim," says he, "Do you know just how fast you were going back there?" Heisenberg smiles. "No, officer, but I know precisely where I am!" *zing* An engineer, a chemist and a mathematician are all staying in the same hotel. Fires break out in each of their rooms. The engineer awakes, sees the fire and immediately reaches for the fire extinguisher. After the flames die down, he thinks to himself, "Thank God I could fix that one," and goes back to bed. The chemist awakes, sees the flames, and immediately reaches for the extinguisher too. With the fire out, he returns to bed, thinking, "It's just as well knew about combustion, or I'd never have known what to do!" (Yes, we chemists are a bit thick...). Finally, the mathematician wakes up. He sees the fire - sees the extinguisher - and goes back to bed, thinking, "Thank God a solution exists!" Kaeroll

I used to like Michael McIntyre on Mock the Week but have never seen his stand-up. My favourites are probably Eddie Izzard (who I am finally going to see this year!), Bill Bailey, Bill Hicks (RIP), and Ricky Gervais. Quite like Frankie Boyle and Ed Byrnes too. Kaeroll

Hi, Perhaps if you provide some more details on what you mean, people may be able to help? I'm not entirely sure I'll be able to - but be extremely careful with HF! It's incredibly nasty stuff. Kaeroll

Hi there. Your answer is not completely wrong at all. If I understand your description correctly (I'm not familiar with 'oxopropane' but I'm guessing you mean a three-carbon acyl chloride), your method is a simple Friedel-Crafts alkylation. It's not a reaction I've ever gotten on with too well, so I'm not sure why you're using Mg/ether, but I trust you have your reasons. The problem with the alkylation reaction is that the MeO is an electron releasing substituent, directing to the p/o positions (or 2 and 4, if you prefer). The product of a single alkylation (likely at the p position for steric reasons) is still activated to further reaction - the alkyl substituent is (debatably) mildly electron releasing too, but in any case certainly does not deactivate the ring. As such, you would struggle to stop the reaction at a single substitution. (Tight stoichiometric control might achieve this, but it's unnecessary faffing about). As you are aware, the 'correct' method is the more efficient acylation followed by reduction. The acylated product is deactivated to further reaction, giving the desired product. Your question highlights an important point in synthetic chemistry - there are often several different ways to obtain a desired product, each with pros and cons. I think it was a bit harsh of your tutor to give you nil points for a reasonable, albeit less practical, alternative. It may be worth discussing this with your tutor and getting their point of view. I have a question of my own now, something I've never properly understood about these reactions - the choice of Lewis acid. Why FeBr3 for alkylation, yet AlCl3 for acylation? I hope this is of some help. Kaeroll