jdurg

Still, a critical mass does not mean that a device will explode like a nuclear bomb. All a critical mass means is that it has the neccessary mass to support a self-sustaining chain reaction. You still need the critical density in order for the chain reaction to ensue. Nuclear power plants all around the world have a critical mass of uranium/plutonium in their reactor cores. Yet these plants aren't exploding like a nuclear bomb. (In reality, they physically cannot explode like a nuclear bomb). The use of conventional explosives in a device is required in order to acheive the critical mass and density needed for a chain reaction explosion. Now you can use hydraulics or other very ineffecient methods, but those haven't been tried in any successful manner and would require a very large building to provide the forces needed.

For a nuclear explosion, you do need a conventional explosive. As YT has pointed out, if you don't have the insanely high density, the freed neutrons simply cannot be absorbed in time and you don't get a self sustaining chain reaction leading to an explosion. What you will get, however, is a critical mass in which enough neutrons do get generated to remove the need for a separate neutron source. In this case, the mass of material will get insanely hot and you will get a meltdown, but then this molten mass of metal will disperse and quickly become subcritical. In a nuclear device, you have subcritical masses which are fused together around a neutron source thanks to conventional explosives. The masses are under such extreme pressure and forces that they fuse into a solid, supercritical mass. Due to the high density of the supercritical mass, the neutrons released are immediately absorbed and very few of them make it out of the 'fuel'. This high density of material causes the explosion to happen. Just because you have a critical mass does not mean you will get an explosion. If that were the case, then nuclear power plants would simply not be possible. (As they run when their fuel supply reaches a critical mass and becomes self sustaining).

Yeah, but if you go and pour yourself a drink in your sodium nitrate crystal cup, you'll have a problem. NaNO3 is VERY soluble in water. Silicon Fluoride is very NOT soluble in water.

When we see the color of a liquid, solid, or gas, it's due to light being scattered by that object. The sky appears blue because of this light scattering, as do the halogens. Chlorine, for example, will scatter the green portion of the visible spectrum more than any other portion, so when you look at chlorine you see a greenish colored gas. Bromine will scatter the red-orange portion of the spectrum so you see the red-orange color better. Iodine is the same with violet. When you look at the periodic table, you can kind of make sense of this. Fluorine and chlorine each have s and p orbitals filling up, so they're fairly similar in that regard. Fluorine is a very pale yellow color and chlorine is a pale green. If you go by the ROYGBIV arrangement of light energies, you'd see that flourine absorbs the lower energy waves a bit better and then scatters them around. Chlorine absorbs the higher energy waves better and then scatters those around. Still, both gases are pretty pale in their colors. When you move down to Bromine and Iodine, you start putting in the d subshells and the colors of those halogens are MUCH more intense. Once again, the lower atomic number halogen has a weaker energy color (Orange) while the higher atomic number halogen has a stronger energy color (Violet). I'm sure there is some correlation between the electron shells and the reasoning behind the color. But when looking at the elements with the same kinds of shells (Fluorine/Chlorine, then Bromine/Iodine) you see that the lower atomic number scatters the lower energy color better. Also remember that the color you see from a halogen is different in origin than the color you see from a metal salt in a flame. Halogens aren't emitting light like an excited metal salt does. A halogen is simply altering how the existing light gets to you. (If you have halogens in a dark room, you can't see their color. If you excite a metal ion in a dark room, you'll see the color as it is emitting its own light).

Yeah, I would also not want to cut sodium under bromine. If my hypothesis that the reaction is stopped by the ultra thin coating of sodium oxide is true, once the pure metal is exposed to the bromine it will rapidly react and you may not be able to get away in time before the bromine is flung onto your skin. In addition, the bromine would probably react with whatever metal your cutting instrument is made out of. With the molten sodium, just be very careful. You may want to melt the sodium in a heat resistant test tube with argon gas sitting over the top of it. (This way the sodium doesn't ignite due to H2O and/or O2 in the air). When you add the bromine just do it one drop at a time. The one problem you may run into is the bromine vaporizing before it can come in contact with the sodium. I myself would also try out this experiment, but my bromine is sealed in a glass ampoule and I also don't have a good place to do any vapor containing experiments as winter is approaching and it's starting to get too cold outside. If you want to have a nice supply of bromine quickly available, I'd suggest getting a small little freezer for your chemicals. Bromine solidifies at 266 K, so if you make a good deal of it you can keep it in a freezer where it exist as a solid and be MUCH less prone to eating through everything. When you need to use some of it, just let it liquify, extract what you need, and place it back in the chemical freezer.

Amorphous silicon is a dirt-brown color. What you probably have is crystalline silicon in a powdered form.

Yes, what you had made was nitrogen-triiodide monoamine (though the exact number of the amine adducts can vary). Secondly, we do not discuss the synthesis of high explosives here at the forums. Doing so is a nice way to get a temporary vacation from these forums.

I'd have to take a look into the reaction between bromine and sodium oxide/hydroxide as the sodium metal will react immediately to form an incredibly thin layer of Na2O on the surface of the metal as soon as you expose it to air. Even if it's just for a few seconds, in the time it takes to wipe off the oil and move the sodium into the bromine, a layer of oxide will form. To really check out whether it's the oxide formation or not, you would need to cut a piece of sodium metal underneath some bromine. However, that could be a VERY dangerous prospect so you may want to avoid that. Another thing to do is to make the sodium molten, and then add the bromine. When I did my NaI synthesis experiment, there were two ways to get the reaction going. One was to add one tiny speck of water, and the other was to heat the metal up to the point of melting. Once molten, adding one tiny crystal of iodine got it roaring. If this is the same as with bromine, then you should be able to test the theory out. If there is any hydroxide on the surface of the metal (which again can form in an instant if there is water vapor in the air), then the halogen will just react with the hydroxide and form a hypo-halogen ion which can further protect the surface of the metal.

Not sure what you mean there, but each element absolutely DOES have a unique spectrum and they do NOT have to be involved in a reaction for that spectrum to exist. In regards to the colors of the halogens, it probably does have something to do with the arrangement of the electrons as each of the halogens does have a color to it and that's a unique trait amongst that group. Since the noble gases right after the halogens are colorless, it would make one think that the one electron short of a full shell plays a part in how the halogens absorb/reflect light.

You can make anhydrous HCl, however, by added concentrated H2SO4 dropwise to a pile of NaCl. HCl gas will evolve from the salt. This is how it's done industrially. (Though they have very large piles of salt and very large 'drops' of anhydrous sulfuric acid).

Mixing hydrogen and chlorine gases to make HCl is an INCREDIBLY foolish thing to do. H2 and Cl2 don't passively combine to form HCl. They explosively combine akin to hydrogen and oxygen. Industrially, HCl gas is produced by the action of sulfuric acid on NaCl and NOT by the combustion of hydrogen in a chlorine atmosphere. Making HCl from its constituent gases is about as productive as making water from its constituent gases.

HCN smells like, rotted, bitter almonds. If you want to know what it smells like, take some almonds and let them begin to rot. You'll then know what HCN smells like because in actuality, incredibily miniscule, picomolar quantities are produced from decaying almonds.

Yeah, the Roto-Rooter brand is typically a good source of sulfuric acid. You can tell if it's a good source when it has bright red warning labels about corrosivity and other warnings. NaOH is indeed a nasty little substance. When making sodium iodide from its pure elements, I had a little blob of molten sodium metal fly onto my right hand. It reacted with my skin and immediately formed a tiny speck of VERY concentrated NaOH. It didn't really hurt all too much right away, but it quickly made a very deep pin-hole in my hand which grew pretty sore over the next few days. I had what probably amounted to a mere nanoliter of liquid sodium on my hand, but it left a pretty significant mark which still shows up today.

I have discovered that a subtle combination of H2Se and HNO3 vapors, when mixed together, is absolutely nauseating. Uggh! I have a bit of some red selenium that was made, but some of the remnant acid vapors remained in the powder so when I opened up the cap of the vial, the odor just knocked me back a good deal. Nasty stuff.

I also believe that ozone would react with the water and decompose into oxygen gas.

Super-Cooling means that a liquid is brought down below its freezing point but still remains a liquid. One degree below the freezing point of a pure liquid is considered 'super-cooled'. It's a similar principle to super-saturation.

akcapr, please try and clean up the wording of your post. I think I understand what you're saying, but it's incredibly difficult to read.

Hydrogen chloride is a gas, so in order to liquify it you would need to compress it, or cool it down significantly. Either way, the liquified gas is incredibly corrosive so it is virtually always transported as a solution in water which is known as hydrochloric acid.

No, you cannot use the store bought charcoal. That stuff is mixed with a bunch of organic compounds designed to let them light easier for grilling. As a source of pyrotechnic 'fuel', they're pretty useless thanks to that lighter-fluid type contamination.

Liquified air, and gases in general, are typically made by compressing and decomporessing the gas/air in succession until it liquifies. I believe this works because the increase in temperature experienced when compressing the gas is a bit less than the decrease in temperature you get when you decompress a gas, so if enough cycles are done the gas liquifies.

Yeah, bromine will eat through typical caps. The ONLY way to store it without any fear of it eating through its container is to seal it in a glass ampoule. Over time, it will eat through any cap and eventually leach out as it evaporates very readily forming a very corrosive and hard to contain gas. I know this from experience as I had bromine eat its way through two containers, one of which was designed for bromine storage. (I ordered quite a bit of bromine from a seller on E-Bay a few years ago and when the bromine arrived it was perfectly fine. A few days later, I noticed a strange stench coming from where I was storing it and could see the bromine vapor leaching out. I quickly contacted the seller who overnighted a new bottle with a teflon cap and various other 'bromine stopping' measures. The bottle arrived the next day and I made the transfer, but the bromine STILL leached through the cap and was corroding the metal container it was then stored in. I finally just wound up sealing a few mL in an ampoule and trading the rest of my bromine for some harder to get elements). The other way to store bromine is to solidify it. If you keep it in an openable container, just store it inside another container in a freezer. As a solid, it's much easier to store. BTW, if you wind up with more Br2 that you want to get rid of, try adding a small piece of Na or K to the bromine. You'll REALLY see a neat reaction take off there.

You need to drink a SUBSTANTIALLY large amount of deuterium oxide in order for ANY physical effects to be seen. In addition, the effects it has on biological processes is caused by its heavier weight than normal water which slows down reactions and can cause problems because a reaction is proceeding to slow to allow it to complete successfully. Again, however, with D2O you need to ingest an enormous amount in order to displace the normal water in a human body.

Actually woelen, in fire detectors they use something like 0.1 microcurie of americium to generate the ionic field used by the detector. No tritium is used at all. Where tritium is used are in exit signs and other important signs which must be visible even if there is no electricity. In those signs, a slurry of a zinc sulfide and tritium doped compound is mixed.