It has come to my attention that some people collect the elements, and even go so far as to put them in grids shaped like the periodic table. Some of these are incredibly unstable, highly corrosive, noxious, radioactive, and downright explosive. The "fun from 3 miles away" side of chemistry!

For my story, I want a cubic 1/2 liter of each element, each fully vacuum-sealed inside an ordinary glass cube, attached to all the others. Each cube is at room temperature, and at 101.325 kPa (sea level pressure of ordinary air.) This table is in extended form; the lanthanides and actinides are included in the bottom two rows. All cubes are inserted at an instantaneous point in time.

I want to know the following about this scenario:

  1. When said elements appear, what will happen? (Pick one you like.)
  2. A human observer is standing 4 feet from the case. What happens to them?
  3. How much would your chosen element's cube cost?

I will edit further according to clarifying comments if needed.


closed as off-topic by DaaaahWhoosh, JDSweetBeat, James, Hohmannfan, fi12 Apr 5 '16 at 21:14

This question appears to be off-topic. The users who voted to close gave this specific reason:

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  • $\begingroup$ Probably way to many questions there. I doubt anything nuclear will happen though. The thing i instinctively would be worried about is the lower left portion, if that stuff gets in water, oh boy the explosion would kill the guy 4 feet away. $\endgroup$ – Ryan Apr 5 '16 at 16:04
  • $\begingroup$ How many elements are you talking about? Are you going all the way to 118? If so, then a ton nuclear will happen. Probably not a critical mass, but a monstrous amount of decay. $\endgroup$ – Lacklub Apr 5 '16 at 17:09
  • $\begingroup$ While this is super interesting, and quite specific, it's too broad. Question 2 alone requires considering 118 or so elements in combination with each other. I think you need to pick one question about this box of elements per post. Also, measuring in liters is a problem. .5 l at what pressure? At what temperature? $\endgroup$ – Schwern Apr 5 '16 at 17:18
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    $\begingroup$ Just question #2 is still way too much to answer here. "When said elements touch air, or each other." The possible combinations are 118! (118 factorial - a truly astronomical number). $\endgroup$ – Jim2B Apr 5 '16 at 18:04
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    $\begingroup$ Randall Munroe spoke about that at his talk at Google: youtube.com/watch?v=7GIDDaF26zE $\endgroup$ – Hohmannfan Apr 5 '16 at 18:04

I'll tackle one, probably the worst one on the list: elemental fluorine.

You can tell who all the sensible chemists are because they have suddenly left the room. The more adventurous ones stay for the fireworks, but have Hazmat on speed dial. Wikipedia mildly explains their concern.

Reactions with elemental fluorine are often sudden or explosive.

Elemental fluorine reacts very exothermically with every other element except neon and helium. It reacts with sand. It reacts with brick. And all at room temperature! Here's a video of that.

This stuff is desperate for electrons, but it won't react with glass... unless your glass is at all wet (and most has some water trapped) in which case it rips away the hydrogen to create hydrogen fluoride, which becomes hydrofluoric acid in water, and it eats through the glass.

If you're "lucky" (50/50 chance) it will eat through the front, back, or top and vent into the room. Now you're "only" worried about hydrofluorine gas. I say "lucky" because it will likely disperse before it can eat through the glass into any of the other elements. For anyone or anything else in the room... well, here's how chemist Derek Lowe of In The Pipeline describes an experience with HF...

It gives terribly painful burns, and it eats through glass, to pick two of its fine qualities. But if you’re going to be precise, hydrofluoric acid is a water solution of hydrogen fluoride, HF. That’s a gas, and it’s a lot worse.

Actually, it’s just barely a gas. In a cool room it’ll condense out as a liquid (it boils at about 20 degrees C, which is 68 F.) The straight liquid must really be a treat, but I’ve never seen it in that form, and would only wish to through binoculars. It’s sold compressed in metal cylinders, like other gases, but it needs some care in packaging. The stuff is so corrosive that special alloys need to be used, usually ones high in nickel. If you stick an ordinary gas regulator on top of an HF cylinder, you’re in for trouble, and the complete destruction of the regulator is the least of your worries.

...The shout “HF LEAK!” went out into the halls, and I’m told that the whole area set a never-to-be-equaled evacuation record. This was one of those drop-things-right-where-you-stand type evacuations, a real sauve qui peut moment.

As bad as HF is, the compounds it can make with other elements are far, far worse. Derek goes on about some of the worst in great detail and from inside a fume hood in the building across the street. Let's say the HF breaks through to a neighbor, what are its options?


One of the few things fluorine does not react with, you lucky skunk.

This, plus the 50% chance it will vent into the room, gives you 66% chance of surviving the day! Because nothing good happens for the remaining two choices.


Chlorine gas is already used as a chemical weapon, and fluorine can only make things better! Did I say better? I meant horribly worse!

At room temperature you get ClF or Chlorine Monofluoride which reacts with metals, but not glass. But since all fluorine reactions are very energetic, and this is happening in a small enclosed space, it may get hot enough to provide some "fun" stuff, ClF3 or Chlorine Trifluoride!

Derek talks about ClF3 in the ominously titled "Sand Won't Save You This Time", here's some choice quotes:

It is apparently about the most vigorous fluorinating agent known, and is much more difficult to handle than fluorine gas. That’s one of those statements you don’t get to hear very often, and it should be enough to make any sensible chemist turn around smartly and head down the hall in the other direction.

The compound also a stronger oxidizing agent than oxygen itself, which also puts it into rare territory. That means that it can potentially go on to “burn” things that you would normally consider already burnt to hell and gone, and a practical consequence of that is that it’ll start roaring reactions with things like bricks and asbestos tile.

There’s a report from the early 1950s of a one-ton spill of the stuff. It burned its way through a foot of concrete floor and chewed up another meter of sand and gravel beneath, completing a day that I’m sure no one involved ever forgot. That process, I should add, would necessarily have been accompanied by copious amounts of horribly toxic and corrosive by-products: it’s bad enough when your reagent ignites wet sand, but the clouds of hot hydrofluoric acid are your special door prize if you’re foolhardy enough to hang around and watch the fireworks.

You can safely assume if ClF3 forms the rest of the case is toast.


Alas, you won't get FOOF at room temperature without electricity being introduced, but you can read Derek's descriptions anyway.

...you run a mixture of oxygen and fluorine through a 700-degree-heating block. “Oh, no you don’t,” is the common reaction of most chemists to that proposal, “. . .not unless I’m at least a mile away, two miles if I’m downwind.”

I'm not sure what fluorine and oxygen produce at room temperature. It's probably extremely energetic and may melt the glass releasing two of the most vigorous reactants into more elements!


Assuming the list only includes those elements found in nature and in the isotopic proportions found in nature:

Question 1

Glass is pretty inert (it is oxidized Silicon) and most chemicals will be contained by it. Be certain to make your glass container strong enough for the vacuum seal.

Fluorine is potentially a stronger oxidizer than oxygen. This means it will etch and eventually eat its way through glass. Here's a video of Fluorine reacting with a number of different chemicals:


Question 2

Not much happens. The glass safely stores all of the elements except Fluorine. Fluorine's corrosion of glass happens slowly. When it finally escapes, the observers will see a faint green cloud of vapor dissipating from the Fluorine container. Depending upon what chemicals are around, the gas will probably dissipate before a violent reaction occurs.

Question 3

Mostly irrelevant.

If your container is made correctly, only the Fluorine will react with the glass. When the Fluorine escapes, it'll make life very unpleasant for the people near your periodic table. Fluorine is corrosive and toxic and will react with most elements and chemicals.

When the Fluorine is inhaled by living creatures, the gas reacts with water on/in its mucus membranes forming hydrofluoric acid. While not a strong acid (NOTE this has a specific chemical meaning, please read the link before disputing this statement), it is still highly corrosive and will begin burning the organism's tissue.

Question 4

No nuclear explosions.

Question 5

No nuclear explosions.

Question 6

Here's a table with the Prices of elements and their compounds.

In summary (dollars per kilogram of element),

  • 10 - 100 Most common elements (a few are cheaper).
  • 1000 - 10,000 Some Rare Earth Elements and some semiconductor materials
  • 35,000 - 90,000 Most expensive of the Precious metals.
  • 130,000 - 500,000 Most expensive of the Rare Earth Elements

The most spectacular reactions occur between elements on the lower left and upper right of the periodic table. This means the most energetic reaction should be between Francium and Fluorine

$Fr + F \rightarrow FrF +$ a light show.

Unfortunately Francium is so rare, there's only about 30 g of it available through the entire mass of the Earth. Since its half-life is 22 minutes, by the time you found your second atom, your first would have already decayed.

About the best you can do is to react Cesium with Fluorine. I found a YouTube video of this:

$Cs + F \rightarrow CsF +$ a light show.


  • $\begingroup$ Also some of your physics, and by some I mean most, as well as your chemistry, don't follow what we know, even for elements we can stabilize. $\endgroup$ – Caleb Woodman Apr 5 '16 at 19:56
  • $\begingroup$ I actually wrote it before hand. However, by the time I hit [Submit], you had already changed the original question. But I do answer your original 6 questions. $\endgroup$ – Jim2B Apr 5 '16 at 19:57
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    $\begingroup$ @CalebWoodman, care to point out a specific problem? $\endgroup$ – Jim2B Apr 5 '16 at 19:57
  • $\begingroup$ It would be very nuclear. Extremely nuclear. all of the elements will be broken free, it just depends on when the nuclear decides to happen. $\endgroup$ – Caleb Woodman Apr 6 '16 at 2:32
  • $\begingroup$ Not when you're using only naturally occurring elements in their naturally occurring isotopic ratios. All of the "very nuclear" type elements are man-made or occur in such small quantities that they wouldn't make the spectacular fireworks that you seem to want. $\endgroup$ – Jim2B Apr 6 '16 at 5:43