Monday, March 24, 2014

March's Element of the Month: Strontium!

March's Element of the Month:


Atomic Mass: 87.62
Melting Point: 777 °C
Boiling Point: 1377 °C

Strontium is a more common element than you'd expect here on the Earth's crust, considering that you don't know the first thing about it.  It's generally ranked as about the 15th or 16th most common crustal element at around 360 parts per million, which makes it about as common as sulfur.  It ain't one of the Big Eight, but it's definitely a major-minor.

There are two reasons you don't know anything about it.  The first is that you have the parochial mindset of the human community, which finds Strontium almost useless.  Once upon a time, it was used in the extraction of beet sugar, and later it was important in cathode-ray tubes.  Its compounds are still used to produce bright reds in pyrotechnics, and in speciality toothpastes, and it is occasionally used in outrageously specialized alloys.  But at the end of the day, it's an element that we could probably manage without.  Literally!  It doesn't have a biological role.  But as interesting as it would be to see what would happen to the planet if all its Strontium was spontaneously removed, I don't think I'd want to be riding when the experiment was conducted.  But I digress.

The other reason you don't know from Strontium is that it is one of those hyperreactive elements that can't stand up to a stiff breeze.  A silvery metal (of course) in its pure form, it immediately turns yellow if exposed to the open air -- kind of like iron turning orange, but much, much faster.  Indeed, if it has been ground to a fine powder it will rust so fast that it bursts into open flame.  It also reacts to water in much the same way that an Alka-Seltzer tablet does.  My point is, surface conditions here on Sol III are just not right for Strontium to be present in its elemental form.  It is diffused throughout the crust.

The Centerfold!

Pure metallic Strontium, preserved in Argon so it doesn't get all oxidized.
Strontium was first recognized as a potential element by a couple of doctors looking for Barium in the Scottish town of Strontian.  After any number of learned men had poked and prodded at the Strontian ore in that charming Enlightenment fashion, it was the irrepressible Sir Humphry Davy who finally isolated the elemental stuff, in 1808, and who definitively named it after the village where it had first been found.  If this raised any hopes that Strontian would be the Scottish Ytterby, they would not pan out, and to this day Strontian remains a one-element village.

I suppose I should mention Strontium-90, a fakey isotope that was among the more problematic components of fallout from atomic bomb testing, the Chernobyl incident, and so on.  Since Strontium is chemically similar to Calcium, sitting right below it on the periodic chart, it is easily incorporated into your bones, which is really not where you want a radioactive source.  The bad news is that there's no avoiding this environmental Strontium-90, which is just as reactive as any other Strontium and so moves with ease through the structure of the planet and its biota.  The good news, though, is that since we're not really testing atomic weapons for the nonce, the ambient level of environmental Strontium-90 drops, according to my seat-of-the-pants math, about a percent and a quarter every year.  That's right, good news about the health of the environment!  You're welcome.

German artist Gerhard Richter has created Strontium, a large-scale mural for the new de Young derived from digitally-manipulated photographs, that together form a geometric black and white motif representing the atomic structure of strontium titanate, a synthetic substance often used to create artificial diamonds. The monumental piece is constructed of 130 digital prints, each one measuring 27-1/2-x 37-1/4 inches, mounted on aluminum with plexiglass coating. It spans a total of 31 x 29.86 feet and is installed in Wilsey Court, the de Young's central public gathering space.

     - Website of the de Young Fine Arts Museum of San Fransisco.

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