collector

Radioactive elements.

I have 30 year old a cataloge from The Radiochemical Centre, Amersham. The stuff they produce (produced) was rather exotic. Most of the chemicals were isotope labeled organic molecules (labeled with tritium, C 14, O 18 etc).

But they also had some interesting compunds of the unstable elements, although not as pure elements, only as chemical compounds.

The compounds are oxides or water souluble salts (nitrates, chlorides).

Examples (quotes from catalog):

Tc 99, as ammonium pertechnetate (NH4TcO4) in 0,1M ammonia, 1mCi £16;

Pm 147, as promethium chloride in 1M HCl, 1-10 mCi £11;

Po 208, as polonium chloride in 1M HCl, 1uCi £78;

Po 210, as nitrat in 3M HNO3, 1mCi £30;

Ra 226, as crystalline chloride, or as bromide in sealed ampoule, total 25-250 mg Ra. Price on request

Ac 227, as crystalline nitrate 1mCi £60

Ac 227 also available as solution in 3M HNO3

Th 228 (radiothorium) as crystalline nitrate, ~100 mCi/mg Th. Price on request

Also available as solution in 3M HNO3.

Th 232 as Th(NO3)4.6H20, 1-10g £30.

Pa 233 solution in 11M HCl/0,5M HF, 1mCi £50

U 232 solution in 3M HCl, ~5 ml, 1-50uCi £56

U233 solid UO2, or solution in 3M HNO3, ~5 ml. Price on request

U 235 (93% enriched): solid UO2 or solution in 3M HNO3, ~5 ml. Price on request

Np 237: as oxide, 100mg £105

Also as solution in 3M HNO3, ca 5 ml, 1 mg £30

Pu 238, solution in 3M HNO3, ca 5 ml. Price on request

Pu 239: as solid PuO2, also available as solution. Price on request

Am 241 as americium oxide, 100 mCi £100, also available as solution in HNO3

Cm 242, solution in 3M HNO3, 1mCi £45

But no berkelium or californium.

I was never tempted to try to get some of these chemicals... (Yikes...!)

But the cataloge was fun.

Potassium

Well, actually, the crust on the potassium ingot had a dirty yellow-brownish tint!! (someone once called it "snot coloured").

Within just a few days the crust was thick. Looked awful.

I realized that this was definitely DANGEROUS, and that´s why I destroyed it.

Later, I got a piece from the same lot of potassium but this time under paraffinum oil. When fresh, the metal did not even sink when immersed in the oil! I had to mechanically push it down under the surface with a thin polyetylene net.

After some days, the metal oxidized, at first a blue-violet surface colour.

Within a week or two the oxide coating was thicker, but this time the oxide was pure white, almost looked like white dust on the metal. And that was definitely K2O.

Fortunately.

About fluorine.

I have been thinking of surface coatings on glass. Now there exist a technique for antireflex glasses, coated with a thin layer of MgF2. And this is one of the very few substances (like CaF2) that withstand chemical attacks from fluorine completely.

So, coating a glass tube with MgF2 or CaF2, could be aa way to permanently seal F2 inside a glass tube. And the same coating on the sealing ends.

And the publication itself:

http://www.usps.com/cpim/ftp/pubs/pub52.pdf

I searched eBay for gallium. Take a look here:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=45721&item=7500606879&rd=1

Remeber that gallium is classified as hazardous material according to USPS Pub 52.

Consequently the hazmat fees...

Back to gallium.

A friend and I once decided to synthezie anhydrous gallium(III)bromide, from direct reaction of the elements.

A sea of molten Ga (~10g) i an glass flask, dripping liquid bromine onto it.

When dripping Br onto the metal, it just inflamed and burned with a red flame (!), the bromine drop fizzing around on the metal surface.

Reminded of a small piece of sodium reacting on a water surface!

And, to much bromine was added at once. A reddish steam was violently thrown out of the flask, togehter with some GaBr3.

Once more, I will never repeat this experiment.

I will stay with collecting elements, not disturbing them!

I will certainly not repeat this either!

Theodore Grays Sodium Party! I think there is a video too.

http://www.theodoregray.com/PeriodicTable/Stories/011.2/index.html

Potassium...

Once (more than 25 years ago) I got a 10g ingot of potassium, unfortunately under kerosene.

That liquid is impure, and the metal coprroded heavily within days!

The oxide quickly forming was a massive grayish crust, which is not the oxide K2O (white), but the dangerous and oxidizing oxides K2O2 (peroxide) and KO2 (hyperoxide).

These are dangerous in contact with oil; cutting in such a piece of metal can initiate a dangerous reaction between the oxide and the oil (litterature says probably not reaction with the metal).

So I decided to destroy it. I put the ingot in a metal can, and a couple of friends and I went to the beach a dark and rainy(!) night. Removed the lid and threw the potassium ingot out in the sea. It started at once with a vigorous evolution of hydrogen, got really hot, and ignited spntaneously within 10 seconds.

The molten potassium got hotter, burning more and more violently. After about 30 seconds it exploded violently with a very loud bang, sputtering burning metal around (still on the water).

My friends were impressed. I was just very pale...

I will NEVER repeat that experiment!

Well...

My own hard experience about collecting elements:

If I had knew 27 years ago what I know today, I would never have gotten into this rather weird and dangerous hobby!

I would collect stamps instead.

Proud!

I have 79 of the 81 elements with at least one stable isotope. After more than 27 years of collecting, with numerous problems and even unpleasant suppliers around the globe.

Today missing: F,Cl, and the black, stable allotrope of phosphorus.

The more exclusive ones are: 2g Sc in glass ampoule from Johnson Matthey, the reactive lanthanides under argon in glass ampoules (La,Ce,Pr,Nd,Eu) from Hamric, beautiful large crystalline ingots of Bi, 10 grams glass ampoules of Rb and Cs respectively (kept locked in a fire proof safe!).

Not so pleasant: a HUGE 1 kg bottle of sodium sticks, analytical grade; 250g potassium, and almost 50g Li. These under paraffinum oil.

And locked away inside the same safe.

Yikes...!

Well, I would like to, but unfortunately it is almost impossible.

It is practically impossible to ship this stuff to almost anywhere.

In the US it has to be shipped according to USPS Publication 52, and so on.

And international shipping is even worse.

I don´t even like to take a look at the bottle, because I am getting a bit ... anxious!

So, I keep it inside the safe, and tries not to disturb it.

Probably, one day I am going to donate it to some institution.

Not so pleasant. Don´t do this!!!

One of the other metals I got in large quantity is - sodium!

Many years ago, I once got an offer I couldn´t resist. Once in a lifetime-offer.

A huge bottle of pure sodium, in large sticks, analytical grade.

The only problem was that I had to buy the hole lot, which was one kilogram...!

I quickly (under some anguish...) repacked the metal sticks under pure paraffinum oil. Original protecting fluid was ligroin. Then I put the huge bottle in a fireproof safe, well locked away. And it will certainly stay there. Forever.

Yikes...!

My own experience.

One of the very few elements I have bought in large quantity is gallium.

About 1300 grams of Ga 99,99% from 2 different suppliers (no, NOT Alfa Aesar).

Price per kg (1992) ~4000 swedish crowns, which is approximately 600 USD.

The purity 99,99% (=4N) has 100 times too high content of impurities for semiconductor purposes.

When melting Ga you soon find that the molten metal it is extremely sticky. This is due to at thin coating of gallium(I)oxide, Ga2O. Melting the metal in air, or even under pure water, is a huge dissapointment!!!

It looks awful, with a dirty crusted soggy skin on the surface. But I soon discovered a treatment.

Like Al, Ga is passivated by oxidizing acids. But melting Ga under a ~5% water solution of a nonoxdizing acid (I used H2SO4, quality "pro analysi" = analytical grade) dissolves the thin oxide coating immediately.

In this state, the metal forms a very beatiful silvery white metal sphere (if you stay with a few grams). Under such a diluted acid, the hydrogen formation on the metal surface is very slow, hardly disturbing, but the oxide is quickly dissolved.

And, in this oxide free form, the metal does not stick to any surface at all!

I used a ~5% water solution of H2SO4, maybe it will work with even more diluted acid.

I melted Ga (about 50g) i a polycarbonate E-flask, first under air. The molten metal really did adhere to the surface, was impossible to remove mechanically. Extremely sticky. Then I added the acid, swirled the flask, and the result was impressive. The adhering metal just fell of the plastic surface, and formed one beatiful silvery molten sea of metal! Even when the metal had formed crusts of white oxide (Ga(OH)3 and Ga2O3 formed when exposed to air and moisture for about a year), these crusts where dissolved by the acid within a few minutes.

Of course this acid treatment slowly dissolves the metal. So, when the metals solidifies, remove the solid and rinse under pure cold water.

I also tried supercooling. When completely pure and dust free, the molten metal (under diluted acid) can be kept in liquid state for months at room temperature.

But when I accidentally dropped a tiny speck of dust (some paper fiber) the molten metal began to solidify within a couple of minutes!

One hour later, the whole mass of metal was solid.

I also discovered a surprising thing about the colour of Ga.

At one time the melt was solidifying (polycarbonate flask), and soon some strange darker blue spots with sharp angles appeared on the plastic surface. When tilting the flask I discovered that these blue spots where crystals forming.

These blue spots formed on the plastic surface inside the melt, on places WITHOUT any contact with air, so it could not be due to oxidation of the metal!

My conclusion from this experiment is that the solid metal is darker than the liquid, with a bluish tint!

Difficult question.

Should 90 Th (the isotope Th 232), and 92 U (the isotope U 238) be regarded as collectable elements?

If making such an exception for 83 Bi, why not for these 2 actinide elements?

The difference is that the instability of Bi is a rather new knowledge, because of its very long half life (difficult measurement).

But it has been known since discovery of radioactivity that these 2 metals are radioactive.

The difference then is quantitative, not qualitative.

Spectrum Tubes, offered for sale by Sargent Welch.

http://sargentwelch.com/product.asp?pn=WLS68755-30W_EA

They offer every (collectable!) gaseous element, except fluorine.

Fluorine in glass tubes (not spectral tubes though), se above.

Have you seen this website?

 

This guy made his own Collection. So far he has 109 elements.

Once more, I restrict myself to the collectable elements, as defined above.

At present time, I have acquired at least one gram of the solids (69 of 69), all of the liquids (2 of 2), and 6 of the 10 gases (gases in spektral tubes).

Some of the refractory metals are usually offered as some ugly powder (Re,Ir,Os etc). By my own "conditions for my element collection", I do NOT accept powders, sponges, or even sintered material.

I ONLY accept solid pieces of the elements, from melted forms. Once more, many of these can be found on eBay.

And of course, all the collectable polymorphic modifications (if applicable) of the elements, e.g. red and white phosphorus.

Unfortunately, black phosphorus is not commercially available, despite being the only stable modification.

Anyone who have found a supplier of black phosphorus??

Where to buy the collectable elements? Try eBay!

Example:

"RARE-EARTH METAL ELEMENT SET. Offered is a complete set of Rare-Earth metal element samples. In this set are 16 unique, fascinating and exotic metals which are rarely or never encountered in everyday life. Until very recently these metals were not available to the general public, except at exorbitant prices for small quantities. Recent improvements in metal separation techniques and wider distribution allow these rare elements to be offered at this price."

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=413&item=6116942430&rd=1&ssPageName=WD1V

Solid pieces of Sc,Y and the lanthanide metals (except Pm)!

Only $120.

Fluorine in glass tubes! http://www.theodoregray.com/PeriodicTable/Elements/009/index.html#sample5

A "complete" element collection does not "contains 92 naturally occuring elements". That is simply impossible!

The most long lived isotope of 87 Fr (Fr 223): half life 22 minutes;

the most long lived isotope of 85 At (At 210): half life 8.1 hours.

On the other hand, uranium (U 238) in minerals naturally produces tiny amounts of 93 Np and 94 Pu. So the "naturally occuring elements" actually are 94, not 92.

By restricting the collection to the elements with at least one stable isotope, the number of "collectable" elements are 80 (1 H - 82 Pb, except 43 Tc and 61 Pm). By regarding 83 Bi as a collectable element, despite its very long half life (2x10^19 y), then there are 81 collectable elements.

Even with such restriction, it is very hard to get a proper sample of every collectable element!

Beautiful collection: http://pse.pniok.de/