I have a special fondness for sodium. Directly or indirectly, you're probably reading this because of my sodium party, which was largely responsible for the popularity of my web site. The party was based on the ability of sodium to separate hydrogen from water, an ability shared by all the elements in the alkali metals group (the left-most column of the periodic table).
If you drop sodium into water, it tears the water apart, releasing hydrogen gas into the air. The hydrogen usually explodes not long after, ignited by the heat released by the sodium during the reaction. Go visit the sodium party and you'll see what I mean.
As with any reactive element, sodium's character is changed completely when it's incorporated into a chemical compound. Let sodium, a reactive metal, and chlorine, a poisonous, choking gas, react with each other (which they do with a violent explosion) and the result is common table salt, NaCl, blowing out all over the place. Isn't the world a wonderful place to live?
Kindly donated by David Franco, who sent many elements after seeing the slashdot discussion, and this one after I sent him some Mathematica t-shirts. Source:David Franco Contributor:David Franco Acquired:11 June, 2002 Price: Donated Size: 0.5" Purity: 99.95%
This is an alarming three and a half pounds of sodium metal in a glass desiccator. The sodium is from eBay and the desiccator is from the Bridgestone/Firestone plant closing auction (the one caused by those faulty tires in 2001). I've briefly removed the lid to take this picture, and used a chisel to make a fresh cut into the metal (which is extremely soft). The cut is at the top right of the picture: It would normally be shiny, but it is so humid here in the summer that it oxidized to white even though I took this picture within five seconds of making the cut. Hence the need for a desiccator (with silica gel desiccant) to store it for any length of time, and even then I'm careful to leave the stopper in loose to relieve gas pressure that could build up from any moisture that remains.
The sound and video for this sample were made during my Sodium Party in the fall of 2002. During this event we dropped about 2 pounds of it, in chunks ranging from 50 grams to 175 grams, into various containers of water. It looked something like this:
Click the story book icon for this sample to read all about the party, and see videos of the many and varied ways in which sodium can explode.
This sodium is too dangerous to keep in the office with the table, and I wouldn't even want to have this much of it around in my shop: If it were to, for example, fall and break on a day when the shop floor has flooded,which happens from time to time, it could easily cause an explosion that would shatter the shop windows. That's another reason for throwing most of this enormous sample into water sometime soon: It's about the only way to make it safe.
Sample from the RGB Set.
The Red Green and Blue company in England sells a very nice element collection in several versions. Max Whitby, the director of the company, very kindly donated a complete set to the periodic table table.
Sample from the Everest Set.
Up until the early 1990's a company in Russia sold a periodic table collection with element samples. At some point their American distributor sold off the remaining stock to a man who is now selling them on eBay. The samples (except gases) weigh about 0.25 grams each, and the whole set comes in a very nice wooden box with a printed periodic table in the lid.
Chips under argon.
Greg thought I since I have such a big page about sodium, I should actually have some *shiny* sodium, not oxidized stuff under oil. So he sent a nice pair of vials with bright sodium under argon. Nice guy, eh? He sells lots of very unusual elements on eBay and elsewhere: Check the Source link for details. Source:Greg P Contributor:Greg P Acquired:1 May, 2003 Price: Donated Size: 1" Purity: 99.9%
High pressure sodium vapor bulb.
The most efficient currently available light sources are arc-discharge lights. The most efficient of all are low-pressure sodium vapor bulbs, but they give a very strongly yellow light that most people don't much like, perhaps because it makes everyone look dead. High pressure sodium lights improve the color somewhat, though they are still distinctly yellow.
This high pressure sodium bulb is sold as a "grow lamp" which means it has a spectrum well suited to encouraging plants to grow. At 1000W, this bulb is large enough to encourage a lot of growing!
This bulb is displayed in my Bulb Stand. Source:Auction Contributor:Theodore Gray Acquired:28 November, 2003 Price: $1 Size: 12" Purity: <1% Sample Group:Light Bulbs
Hollow cathode lamp.
Lamps like this are available for a very wide range of elements: Click the Sample Group link below to get a list of all the elements I have lamps like this for. They are used as light sources for atomic absorption spectrometers, which detect the presence of elements by seeing whether a sample absorbs the very specific wavelengths of light associated with the electronic transitions of the given element. The lamp uses an electric arc to stimulate the element it contains to emit its characteristic wavelengths of light: The same electronic transitions are responsible for emission and absorption, so the wavelengths are the same.
In theory, each different lamp should produce a different color of light characteristic of its element. Unfortunately, the lamps all use neon as a carrier gas: You generally have to have such a carrier gas present to maintain the electric arc. Neon emits a number of very strong orange-red lines that overwhelm the color of the specific element. In a spectrometer this is no problem because you just use a prism or diffraction grating to separate the light into a spectrum, then block out the neon lines. But it does mean that they all look pretty much the same color to the naked eye.
I've listed the price of all the lamps as $20, but that's really just a rough average: I paid varying amounts at various eBay auctions for these lamps, which list for a lot more from an instrument supplier.
(Truth in photography: These lamps all look alike. I have just duplicated a photo of one of them to use for all of them, because they really do look exactly the same regardless of what element is inside. The ones listed are all ones I actually have in the collection.) Source:eBay seller heruur Contributor:Theodore Gray Acquired:24 December, 2003 Price: $20 Size: 8" Purity: 99.9% Sample Group:Atomic Emission Lamps
Molten blobs under argon.
Ampouling sodium in a clean and dry enough environment to keep it shiny is difficult. This sample demonstrates great skill in its ampouling, especially since it was done using only "the simplest methods", according to the source. Source:Frank Liebscher Contributor:Frank Liebscher Acquired:28 January, 2004 Price: Donated Size: 3" Purity: 99.9%
Cut cubes under oil.
This is a sample I prepared specifically for a film project, to make a 360-frame rotation image. It's ordinary scrap sodium from my anonymous supplier, but this piece has been carefully cut under oil to reveal a shiny surface. Because the vial it's in is not flame-sealed, oxygen will eventually works its way in and the sample will become oxidized. But for my purposes, as long as it stayed shiny for half an hour that's all I needed.
I chose this sample to represent its element in my Photographic Periodic Table Poster. The sample photograph includes text exactly as it appears in the poster, which you are encouraged to buy a copy of.
Liquid sodium metal is used in certain nuclear reactor designs as a cooling fluid, because it is very effective at transferring large amounts of heat from one place to another. Personally I'd rather have something a bit less violently explosive as the cooling fluid in my nuclear reactor, but so far as I know there haven't been any major accidents attributed to its use.
This object, which also uses liquid sodium metal for cooling, is not from a nuclear reactor. Is is a valve from a high-performance car engine, and it uses the sodium to transfer heat away from the valve head (which is in contact with the exploding fuel in the cylinder). This particular value has been broken in half to extract the sodium: You can see the hollow stem where the sodium was.
Look at the next sample down to see more clearly how this channel works. Source: Nick Brandenburg Contributor: Nick Brandenburg Acquired:10 August, 2005 Price: Donated Size: 5" Purity: 0%
This is an engine valve from a high performance car engine. A 90 degree wedge of the valve stem has been machined away (using a solid tungsten carbide end mill under a flow of water-free, petroleum-based cutting fluid), showing the hollow channel and its contents of sodium metal.
The metal is solid now because the valve is cold, but because the melting point of sodium is quite low, it will liquefy as soon as the engine starts to warm up, and after that the sloshing of the liquid metal up and down in the hollow channel serves to transfer heat from the valve head (which is in contact with the exploding fuel in the cylinder) to the valve stem, which in turn transfers the heat further out of the engine.
In this photograph the sodium is just slightly oxidized from exposure to the air, but when freshly cut under oil, it was bright, indicating a fairly high degree of purity. And when I dumped the collected metal chips (carefully) into a cup of water, they sizzled and popped, confirming that the contents of the channel really are sodium metal.
After I finished taking pictures of this sample, I left it alone for the Thanksgiving long weekend, after which the sodium had oxidized further. It still had a coating of oil, and the air was quite dry, otherwise it would probably have converted entirely to oxide by then (sodium is extremely hygroscopic, and even with the oil and dry air, there was a good bit of highly alkaline liquid around the remaining metal).
To make the sample safe, I needed to clean out the remaining sodium, which I decided to do by slowly exposing it to drops of water over the kitchen sink. This was not a good idea. Actually, I did pretty well with the valve itself, after I had used a fork to dig out most of the sodium: It sizzled quite a bit and the valve stem got warm, but I never let it get hot enough to actually catch the evolved hydrogen on fire.
The problem originated with the few small clumps of sodium I took out with the fork. I put them on a paper towel, which was kind of dumb. Then I decided it was such a small amount, I would just run water over the towel and let them fizzle out. Needless to say, the paper towel caught fire and blobs (small ones, I should say in my defense) of flaming sodium popped in all directions including falling into the drain, where they made ominous echoing sounds as they filled the drain hole with smoke.
OK, I admit it, I set the kitchen on fire with sodium. I, of all people, should know better! But it wasn't very much fire, and you are not going to tell my wife where the scorch marks on the floor mat came from. If you have any doubt that engine valves can actually contain sodium metal, let me assure you, they can. Source: Nick Brandenburg Contributor: Nick Brandenburg Acquired:10 August, 2005 Text Updated:29 January, 2009 Price: Donated Size: 5" Purity: >98%
This interesting bulb, meant for indoor plant growing operations, combines two different arc discharge tubes in one, to provide a wider spectrum of light than either type would alone. One is a high-pressure sodium arc, the other is a metal halide tube, probably containing scandium as a spectrum-enhancer. Source:eBay seller garden_supply Contributor:Theodore Gray Acquired:2 April, 2009 Text Updated:3 April, 2009 Price: $94 Size: 12" Purity: <2%
Ah, the internet, what would we do without it? Sodium ducks for crying out loud! Get yours at ExplosiveMetals.com. They must get really tired flying non-stop, but they're pretty motivated since if one of them ever landed on a lake, they would explode. Source:Alan Halls Contributor:Alan Halls Acquired:22 April, 2009 Text Updated:23 April, 2009 Price: Donated Size: 3" Purity: >98%
Drain opener (foaming).
This is sodium hydroxide-based drain opener with a twist. See the little shavings? Those are probably either magnesium or aluminum, which will generate hydrogen gas when the sodium hydroxide is dissolved in water, creating a foaming action. At least, I think that's the idea. Source:Farm & Fleet Contributor:Theodore Gray Acquired:28 June, 2009 Text Updated:29 June, 2009 Price: $10 Size: 2" Purity: 56%
Tourmaline (Dravite variant).
I'm not sure why I have this mineral: I think it may have been a free sample included with some other mineral purchase. Lovely, though of relatively undistinguished chemical composition. Source:Theodore Gray Contributor:Theodore Gray Acquired:20 September, 2005 Price: Donated Size: 1" Composition:NaMg3Al6(BO3)3[Si6O18](OH)3(OH)
See above Actinolite sample for an extended discussion of asbestos, mesothelioma, lawyers, and litigation.
Mineral details: Riebeckite (variety Crocidolite), amphibole group, double-chain silicate. From the Greek krokid ("nap on woolen cloth"). Kuruman, Northern Cape Province, South Africa.
Description from the source:
Eudyalite (Na4(CaCe)2(Fe+2Mn+2Y+ZrSi8O22(OHCl)2 trig.), Kipawa Alcalyne Complex, Villedieu Tow., Quebec, Canada. Red, granular, with white fibrous Agrellite and beige Vlasovite. A rich thumbnail. 2,2x1,7x1 cm; 5 g. Source:Simone Citon Contributor:John Gray Acquired:26 September, 2008 Text Updated:28 September, 2008 Price: Trade Size: 0.85" Composition:Na4(CaCe)2(Fe,2Mn,2Y).ZrSi8O22(OHCl)2
Description from the source:
Sulphohalite ( Na6 (SO4)2 F Cl cub.), Searles Lake, California, USA. Perfect octahedral crystal, much better than the photo, rare. 2x1,8x1,5 cm; 12 g with box. Source:Simone Citon Contributor:John Gray Acquired:26 October, 2008 Text Updated:26 October, 2008 Price: Trade Size: 0.75" Composition:Na6(SO4)2FCl
Soda-lime glass Medallion.
I made this medallion for an article in my Popular Science column, using a charcoal grill to melt the ingredients (silica sand, washing soda and limestone) together into soda-lime glass. Once melted I pressed the glass (darkened by ashes from the fire) into a graphite mold I had machined and heated in the fire. Source:Theodore Gray Contributor:Theodore Gray Acquired:26 October, 2008 Text Updated:26 October, 2008 Price: $1 Size: 2.5" Composition:SiO2+Na2CO3+CaCO3
Description from the source:
Ulexite (Na Ca B5 O6 (OH)6x5 H2O tric.), Boron, California, USA. When viewed parallel to the fibers, Ulexite transmits light in a similar fashion to fiber optics. 3,2x1,5x1 cm; 8 g. Source:Simone Citon Contributor:John Gray Acquired:27 December, 2008 Text Updated:28 December, 2008 Price: Trade Size: 1.25" Composition:NaCaB5O6(OH)6.5(H2O)
Description from the source:
Elbaite (Na (Li Al)3 Al6 (BO3)3 Si6 O18 (OH)4 trig.), Minas Gerais, Brazil. Isolated, terminated crystal with rare pink-orange color. 2,3x0,8x0,8 cm; 4 g. Source:Simone Citon Contributor:John Gray Acquired:28 January, 2009 Text Updated:29 January, 2009 Price: Trade Size: 1" Composition:Na(LiAl)3Al6(BO3)3Si6O18(OH)4
Description from the source:
Halite (Na Cl cub.), Stassfurt, Germany. Interesting deformed cube, from a very old collection. 3,2x1,4x0,5 cm; 5 g. Source:Simone Citon Contributor:John Gray Acquired:28 January, 2009 Text Updated:29 January, 2009 Price: Trade Size: 1.25" Composition:NaCl
50 pound salt block.
This 50 pound block of salt cost $4.99. That's right, 10 cents a pound retail for something once so valuable that the very word salary derives from it. In solid block form salt like this is meant for licking by cattle. It's called a salt lick and you get them at farm supply stores. Source:Farm & Fleet Contributor:Theodore Gray Acquired:28 February, 2009 Text Updated:1 March, 2009 Price: $5 Size: 12" Composition:NaCl
Salt from Death Valley.
You're not supposed to take salt from Death Valley, it's a national park. First name only on the source. Tastes very salty, yuck! Source: Kat Contributor: Kat Acquired:2 April, 2009 Text Updated:3 April, 2009 Price: Donated Size: 4" Composition:NaCl
Himalayan sea salt.
There is a list of 84 elements that seems to pop up repeatedly in the ingredient lists of "natural" mineral products, supplements, pills, and the like. Even, it turns out, in salt. Here then is the list of minerals claimed to be found in all-natural organic Himalayan sea salt:
I wish someone would tell these people that, for example, neptunium and plutonium do not occur in nature at all, let alone in salt. Unless, I suppose, if you count nuclear fallout as a "natural" source of ingredients.
What bothers me most is what this says about the level of scientific literacy, both of the people selling the stuff, and the people buying it. Does no one actually read the list? Or do they read it an not realize how preposterous it is? It's enough to make you despair for the future of mankind.
Pretty salt, though. Source:eBay seller saltwonders Contributor:Theodore Gray Acquired:28 March, 2009 Text Updated:4 April, 2009 Price: $15 Size: 0.25" Composition:NaClSbCsDyErEuGdHfHoInLaLuNdPrSmScThTlTeTbTmYbY