Sciencemadness Discussion Board

Caesium sample in a little ball

wotaen - 3-8-2015 at 22:55

I obtained this for my element collection:
http://onyxmet.com/image/cache/data/2015%202/Cs%208g-800x800...

Molten metal covered the entire glass ball so no solid state is visible. When it's cold enough for the sample to be solid, I can feel the piece inside when I shake the ampoule. So the question is...is it possible to clear the sides of the glass so the solid piece is visible? My only idea was to warm it slightly and hope for the metal to unstick from the glass walls...however I'm not sure if it would help and how hot can I go (I sure don't want to go above boiling point)

Thanks

diddi - 3-8-2015 at 23:21

it is easy to melt. only need hot water in a cup
warm it up and it should be fine.
it should change colour too a bit to a golden silver

ave369 - 4-8-2015 at 00:03

You can also order another sample and break the ampoule in water. Remotely, because it makes a boom. This way you will synthesize cesium hydroxide, which is an interesting, ultra strong alkali. The strongest aqueous base; everything stronger than that is a superbase and reacts with water. Be careful, it attacks glassware faster than hydrofluoric acid, turning it into cesium waterglass.

You can also try to synthesize cesium ozonide, which is the most stable ozonide in normal conditions.

In any case, cesium has a lot of interesting properties to experiment with. Making it just sit on the shelf and do nothing is boring.



[Edited on 4-8-2015 by ave369]

woelen - 4-8-2015 at 02:17

@wotaen: That is a very nice sample, I have never seen such samples before. It also contains a lot of Cs. Be careful not to break the sphere of glass when you heat the bulb.

@ave369: Cesium hydroxide is not much different from KOH or NaOH. I have some CsOH and did some experiments with it. It dissolves in water just like KOH and its solutions are not more corrosive than solutions of KOH of similar concentration. You can do experiments in glass without problem with this compound. If its solution is hot and concentrated, it slowly attacks glass, but that is true also for the other alkali hydroxides. You have to be careful with CsOH, just as with other alkali hydroxides, not more, not less.

Hydrofluoric acid at high concentration (50% or so) is a totally different beast. It eats glass quite quickly and can even eat itself through a test tube in a few minutes.

wotaen - 4-8-2015 at 03:42

Quote: Originally posted by woelen  
@wotaen: That is a very nice sample, I have never seen such samples before. It also contains a lot of Cs. Be careful not to break the sphere of glass when you heat the bulb.


The seller 'onyxmetal' cought on the wave of element collecting and now provides a lot of samples in variants useful only for element collectors. As of today, they have beautiful gas balls. That one sample contains about 8grams of Cs.
You mentioned being careful not to break it....from the apparent option of dropping it or breaking the tip of the glass ball, are there any other things to watch out for? Obviously I'm not going to do it over direct flame, but dipping in hot water shouldn't hurt, right?

Btw, as for alkalis in water, simple sodium tiny piece in near boiling water gives a nice, loud bang and doesn't make a hole in your pocket :). If you leave enough room above the water surface for the smoke to form, it gives you a very nice ring...Gandalf would be ashamed...it rose up a few meters, beautiful

[Edited on 4-8-2015 by wotaen]

[Edited on 4-8-2015 by wotaen]

Pok - 4-8-2015 at 07:26

It could depend on the cleanliness of the glass inside and on the purity of the caesium (e.g. contaminated with oxide). If one of these variables is not sufficient high, it is possible that you will never get rid of the "sticking to the glass" effect. I wouldn't recommend to put in in hot water. If the ampoule brakes you will have a serious problem. But you can put it in another small cointainer which is fireproof and put this container in warm water. I also have a cesium ampoule which is covered with Cs when shaken (after all Cs is liquid). But after some seconds or minutes of immobility (while still liquid) the metal seperates from most parts of the glass again. If this doesn't work in your case, one of the above mentioned variables could be not sufficient. In this case you could try to "centrifuge" (but not shake) the ampoule with the molten metal in your hand so that you inrease the gravity inside the ampoule which could allow the thin liquid metal coat to rip on one side.

Camroc37 - 4-8-2015 at 19:19

Where did you buy it?It is very pretty. The most difficult decision is whether to break it over water or to keep it!

j_sum1 - 4-8-2015 at 19:27

located at www.onyxmet.com. Great company. Click on Cs on the periodic table and scroll down and you will see the same pic. Only 650 polish zlottis for 8 grams if you want to get your own.

woelen - 4-8-2015 at 23:15

I would never heat the bulb directly. If the heating is uneven, then strain in the glass may cause it to crack. Pok's suggestion is fine. It is much safer and if there is breakage you do not get an explosion.

[Edited on 5-8-15 by woelen]

Dan Vizine - 10-8-2015 at 15:42

Notice to all that say cesium is golden. It isn't (see the picture). Only the oxide is. Melting the Cs won't change the color.

Since your Cs is 99.9% it may wet glass somewhat (due to Na impurity). Capillarity may complicate things. Heat stem with heat gun on low. If sealed under vacuum, the Cs will migrate slowly, if under inert gas, no such luck. Maybe the previously mentioned centripetal acceleration will work then.

It's apparent that they (or whoever they buy from) have high vacuums available to them (higher than a two stage vacuum pump). This requires an oil diffusion pump or, more likely nowadays, a turbo pump, to achieve the vacuum that will allow further distillation into other parts of the apparatus to purify it.

How I long for a turbo-pump......it's the way to distill the next tier of metals....Cs in glass, Barium, strontium and calcium in steel. Even Li. Supposed to be highly reactive when distilled like this according to Brauer. Also very pretty.

It's not been my experience that Cesium explodes in air, it's more of an energetic conflagration. No boom whatsoever. Water is, naturally, very violent in reaction and never advised. The safest liquid to warm it in is dry mineral oil. Small splits in Cs vials often proceed slowly with a rainbow display within. Larger ones with fires. Seven or eight grams is a sizeable fireball in air, I'm estimating a foot from all the 1 and 2 gram vials that weren't perfect and so we threw them at stone walls. The initial fire is over very quickly.

Recently it's been hypothesized, and maybe even proven, that these metals in H2O undergo an explosion driven as much by charge concentration as sheer chemical energy. They term it a columbic explosion. Crazy spikes of an almost fractal pattern jump out. Then explode.

[Edited on 11-8-2015 by Dan Vizine]