Sciencemadness Discussion Board - The Halogens and Alkalis Confined! (Pictures)

The Halogens and Alkalis Confined! (Pictures)

Jdurg - 18-11-2006 at 16:09

I while back I had made mention about how I had an ampoule of bromine that was slowly leaking and emitting a nasty bromine odor. I brought the ampoule to a friend of mine who has the ability to ampoule samples as well as cast them in an acrylic resin of sorts. Thinking about that, I asked him if it would be possible to cast an ampoule of each halogen into the same resin block? Of course fluorine gas would be a no-no, but a Calcium Fluoride powder would be a representative sample. The nice thing about having the ampoules in resin is that it provides an extra barrier of protection against them, as well as the fact that bromine can't seem to seep through or attack the resin. (I was shown a failed attempt at making a resing piece a few years ago where the casting pressure broke the glass. The bromine leaked out and filled the spaces around the glass, but it wasn't leaching through the resin).

Anyway, I was without all of my halogens for quite some time while the resin piece was cast. I was kind of starting to miss them.

Finally, this past week I was reunited with my old friends in the form of a BEAUTIFUL cast resin block of each halogen. The block is 124mm wide by 30mm thick by 150mm tall. It's actually very heavy which surprised me but that also keeps it nice and secure. I'll eventually figure out a way to heat up the iodine so that it sublimates and only crystalizes down at the bottom. For now, the chlorine is faintly green as it should be (I have some liquid chlorine which really shows off its color), the bromine is nice and secure, and the iodine is bespeckling the glass it's in. In the future I plan on putting some walnut trim pieces around the edge with a nice base and top so that it will stand out as a nice display piece.

Edited title to make it more descriptive!

[Edited on 21-11-2006 by chemoleo]

Halogens.jpg - 62kB

Jdurg - 18-11-2006 at 16:13

In addition to the Halogens, I also picked up a five gram ampoule of Rubidium metal to match my Cesium metal ampoule. When side-by-side, it's really interesting to see just how much denser cesium is. Both ampoules contain five grams of metal, but the rubidium is noticely larger in volume. What's also odd is that the rubidium shows small splotches of oxidation within the ampoule. These brownish colored areas on the photograph only seem to show up in pictures. When holding the ampoules in hand I cannot see the color variation. Interesting. Since these came from a scientific supply house, it really shows off how reactive these buggers are if even they can't keep it 100% oxide free. (In addition, these ampoules are intended to be used which is why they have the pre-scored area in the neck of the glass to make it easy to break. This is why I'm kind of nervous about handling them too much. One gram of Rb or Cs isn't too much to worry about, but Five Grams of Rb AND Cs falls into the "Uh-Oh" category if an accident were to happen).

Jdurg - 18-11-2006 at 16:14

Here's a close-up image of the Rubidium Ampoule.

Rubidium.JPG - 48kB

Jdurg - 18-11-2006 at 16:16

Finally, a close-up of the cesium. Mmmmm....... Liquid Gold........

JohnWW - 18-11-2006 at 16:25

Halogens? How about trying to get your hands on some astatine (element 85), to complete the collection? Only problem is, its two longest-lived isotopes both have half-lives of only about 9 hours. It chemically resembles I, forming an At- anion, and forming organic compounds, certain of which, like those of I, can act as thyroid hormones; except that its (VII) oxidation state is much more difficult or impossible to obtain.

Jdurg - 18-11-2006 at 16:34

Quote:

Originally posted by JohnWW
Halogens? How about trying to get your hands on some astatine (element 85), to complete the collection? Only problem is, its two longest-lived isotopes both have half-lives of only about 9 hours. It chemically resembles I, forming an At- anion, and forming organic compounds, certain of which, like those of I, can act as thyroid hormones; except that its (VII) oxidation state is much more difficult or impossible to obtain.

Yes, I am well aware of astatine. But trying to include that in a collection is like trying to include francium in a collection of the alkali metals. It just aint going to happen.

Though there are many actinides which have isotopes well long enough to obtain a sample of. If only their radioactivity wasn't so high energy.

The_Davster - 18-11-2006 at 16:54

Nice samples, I have been intending to ask a proff of mine to order me a 5g ampoule of Cs from Alfa. To bad noone sells teflon lined amoules of pressurized liquid fluorine...

Jdurg - 18-11-2006 at 17:22

Well you can get fluorine gas sealed into a glass ampoule, but it requires a great deal of work and some special chemicals to protect the glass. The other option is to get a mixture of 67% He and 33% F2. For some reason I can't understand, that mixture will allow fluorine gas to be stored in a glass ampoule without the glass being destroyed. The problem with diluting that far is that you really can't see the natural VERY faint yellow color of F2.

The Cesium is incredibly pure as its melting point is very sharp. Once it is warmed up above its metling point, the whole thing liquifies. My older, not so pure, sample would mostly melt, then the other parts would melt. They really are beautiful samples. I'd love to get them cast in a resin block as well, but the glass walls are so thin around the neck that the curing resin would exert enough force to shatter the glass. That's a shame because while I currently have a halogen block I'd love to have a matching alkali block.

I'm just really psyched right now that I have nice, oxide free samples of every alkali metal except potassium and I should be able to get a sample of that soon. It's also kind of frightening knowing that I have a gram of rubidium and about 25 grams of sodium metal in my closet.

I'll need to figure out a fun way to get rid of that extra rubidium.

Pyrovus - 18-11-2006 at 19:46

Quote:

Perhaps if you were to mix bismuth with a suitably high energy alpha emitter like radium or something. That way, when the radium (or whatever) decays, some of the alpha particles might be captured by the bismuth and produce astatine, so you might end up with an equilibrium quantity of a few million astatine atoms. True, it's a long way from having a visible quantity of the stuff, but I very much doubt anybody's ever managed to synthesise a visible quantity of it, and it's probably the closest you could get. Besides, even if you could get a visible quantity of it, it would likely be producing so much energy from alpha decay that you wouldn't really be able to get a good idea of what astatine crystals look like. The heat and light produced by the radioactive decay would completely overwhelm the light which reflects off it, for instance, so you'd have no idea as to it's natural colour. All you'd really have would be a glowing white hot ball of destruction which incinerates everything that gets within a few metres, which is probably what all other similarly unstable elements would look like if you could get visible quantities of them.

[Edited on 19-11-2006 by Pyrovus]

12AX7 - 18-11-2006 at 21:52

I've been wondering what a cylinder of tritium looks like, on the inside I mean. Since tritions decay to 3He and a 16keV (I think) electron, it should give off bremsstralung (sp) and have the energy to excite a whole bunch of atoms, giving off spectral glow without electric discharge (it IS its own discharge

).

Tim

Jdurg - 19-11-2006 at 10:16

Yes, tritium does give off electrons when it decays which is why we can use it in illuminated signs (such as exit signs in hospitals) and in certain types of glowing key chains. This way, if there is a loss of power the way out will still be visible.

woelen - 19-11-2006 at 14:21

Jdurg, these samples look very nice. I really like your Rb and Cs samples. I still don't have any of these metals. Sad that you live in the USA, otherwise I would consider buying your 1 gram Rb sample, but I don't think it is a good idea to ship this sample to Europe. There simply is too much chance of getting trouble with that.

I have found a supplier in Europe, who sells a 1 : 2 mix of F2 and He in large glass ampoules. I've seen pictures of those samples, but you really can't see the F2, and that is sad. I am thinking more and more that a real good F2 sample will remain a gap in my element collection. I have some NaF, KF and also KHF2, but these are not good replacements to my opinion of F2. Maybe some NaF, and a dilute Cl2 atmosphere above it, to get the idea of the color of F2? Or is the color of dilute Cl2 too much different from the color of F2? Maybe a mix of Cl2 with a tiny amount of Br2 to make the vapor more yellow. Of course, this is cheating, but with the solid NaF in it (or CaF2 as you have) it is clear that fluorine is not easy to have, but then at least one can get the idea of the color of F2-gas by a suitable Cl2/Br2/air mix. What is your idea about that?

Jdurg - 19-11-2006 at 15:44

Thank you for the kind words woelen. The Rb and Cs are some of my favorite samples and not just because of their "new" factor. I just wish that the ampoules they were in had a bit more heft to it. I'm always afraid to handle them too much in fear of the breakseal ampoule opening up. I wonder how much force it takes to break the necks there?

In regards to the shipping of the sample to Europe, what are the chances that the package would be opened? In addition, what is the worst that would happen? You have my e-mail address, so feel free to e-mail me and perhaps we can work something out so that I can get the 1-gram Rb sample out to you. While right now the sample has a date with a shallow pan of water, I would rather it go into the hands of a collector.

As for the fluorine sample, I think a good substitute would be some crystals of XeF2. The only thing I'm not sure of is how corrosive to glass that compound is. If it can be stored in glass, or glass encapsulated with resin, that would be a neat way to show off a fluorine compound AND a Xenon compound. In regards to using dilute chlorine to produce a faint yellow to represent fluorine, I don't think that would work. Chlorine, when dilute, is barely noticeable at all unless a white background is placed behind it. Then, when you look through a good deal of it or look at it with the background it is just to distincly green. Also, the bromine addition would be too intense to represent fluorine. From what I've seen, fluorine gas is like chlorine in terms of color intensity, but distinctly yellow.

The_Davster - 19-11-2006 at 16:02

If the metal is not tight in the glass, it will shake around breaking the ampoule. Had it happen with another metal, which luckily was not air reactive, just toxic, and secondary containment in a plastic baggie was successful. With one of these metals if it ends up out of the vial....uh oh...

Jdurg - 19-11-2006 at 18:42

Heh. These Rb and Cs ampoules were filled with molten metal which is stuck inside quite solidly.

Fleaker - 19-11-2006 at 18:42

Just thought I'd mention this:

very cool video of the reaction of the alkali metals. It goes down the periodic table, ending with cesium

Under "external links" at the bottom of the wiki page for rubidium you will see it.

http://en.wikipedia.org/wiki/Rubidium

Jdurg - 19-11-2006 at 18:46

Quote:

Originally posted by Fleaker
Just thought I'd mention this:

very cool video of the reaction of the alkali metals. It goes down the periodic table, ending with cesium

Under "external links" at the bottom of the wiki page for rubidium you will see it.

http://en.wikipedia.org/wiki/Rubidium

Very cool and actually realistic unlike the crap shown on Brainiac. It's just a shame that their color balance is horrifically off as the water looked green and the colors of lithium and sodium looked the same because of the off-color balance. Still, nice video.

The_Davster - 19-11-2006 at 18:58

I remember reading, can't even remember if the source was reputable, that the cesium video was 'enhanced' by shooting the dish with a pellet gun.

Theodore Gray has some cesium videos on his site for comparison.

Elawr - 19-11-2006 at 19:27

Would it not be cool to have a sample of radon in glass - in the liquid phase?!?!

[Edited on 20-11-2006 by Elawr]

Jdurg - 19-11-2006 at 19:38

Quote:

Originally posted by The_Davster
I remember reading, can't even remember if the source was reputable, that the cesium video was 'enhanced' by shooting the dish with a pellet gun.

Theodore Gray has some cesium videos on his site for comparison.

It's all a matter of the physical shape of the container the item is dropped in, as well as the temperature of the water. Thin walled glass vessels, like the one the Cs was dropped in, are more likely to break than thicker glass vessels. In addition, if you up the temperature of the water you'll get a more vigorous reaction. Unfortunately, we are missing two important items here; the temperature of the water and the mass of the cesium. If the container it was stored in had a weak point, the pressure caused by a rapidly forming bubble of hydrogen and gaseous water could crack it right there.

When you look at Theodore Gray's experiments, he's using pretty hefty containers to hold the reaction in. I don't recall seeing him use a glass container.

Jdurg - 19-11-2006 at 19:43

Quote:

Originally posted by Elawr
Would it not be cool to have a sample of radon in glass - in the liquid phase?!?!

[Edited on 20-11-2006 by Elawr]

It could be done, but it would be kind of difficult since it decays with a relatively short half life and your glass ampoule would soon become clouded by the decay products. (I think the longest lived isotope has a half-life of around four days).

chemoleo - 20-11-2006 at 19:56

I edited the title to make it more descriptive.

Jdurg, have you tried freezing your Cs sample really really slow?
I wonder whether you'd be able to get Cs crystals, this would be absolutely awesome!

pantone159 - 20-11-2006 at 20:45

Quote:

As for the fluorine sample

Personally I am a fan of octahedral crystals of CaF2 as my F sample. I think the natural crystals, which are very nicely shaped, and often colored a nice purple (from an impurity of course) have a coolness factor which nicely offsets the not-actually-pure factor.

Jdurg - 21-11-2006 at 06:08

Quote:

Originally posted by chemoleo
I edited the title to make it more descriptive.

Jdurg, have you tried freezing your Cs sample really really slow?
I wonder whether you'd be able to get Cs crystals, this would be absolutely awesome!

Actually, I did do that with my cesium sample that I "upgraded" to this newer sample. When it would melt, it would melt such that the crystalline parts would remain as a crystal and the liquid cesium would flow away from it. (Unfortunately all of the liquid cesium picked up the bits of dust and contamination inside the glass which eventually dirtied it up a bit. I'd rather not have my clean, 5N+ sample get dirty).

Jdurg - 25-11-2006 at 20:10

After looking through some of the images in wikipedia, I've decided to go and upload some of my photos there as they look much better than the crap currently listed. Thus far I've uploaded my thorium and cesium photos. I haven't uploaded the rubidium yet as I'm trying to get a picture of it without the odd brown discolorations.

(EDIT: Okay. I've now replaced their poor quality standard photos of sodium and cesium with my much better quality images. In addition, I have provided my photo of thorium metal and have used my image of the peroxides/ozonides on my potassium metal chunk as well. I guess I've finally put my element photos to good use.

)

[Edited on 26-11-2006 by Jdurg]