Sunday, November 18, 2012

"The Chemistry Behind Commodity Money"

From NPR:

A Chemist Explains Why Gold Beat Out Lithium, Osmium, Einsteinium ...
The periodic table lists 118 different chemical elements. And yet, for thousands of years, humans have really, really liked one of them in particular: gold. Gold has been used as money for millennia, and its price has been going through the roof.

Why gold? Why not osmium, lithium, or ruthenium?

We went to an expert to find out: Sanat Kumar, a chemical engineer at Columbia University. We asked him to take the periodic table, and start eliminating anything that wouldn't work as money.

The periodic table looks kind of like a bingo card. Each square has a different element in it — one for carbon, another for gold, and so on.

Sanat starts with the far-right column of the table. The elements there have a really appealing characteristic: They're not going to change. They're chemically stable.

But there's also a big drawback: They're gases. You could put all your gaseous money in a jar, but if you opened the jar, you'd be broke. So Sanat crosses out the right-hand column.

Then he swings over to the far left-hand column, and points to one of the elements there: Lithium
"If you expose lithium to air, it will cause a huge fire that can burn through concrete walls," he says.
Money that spontaneously bursts into flames is clearly a bad idea. In fact, you don't want your money undergoing any kind of spontaneous chemical reactions. And it turns out that a lot of the elements in the periodic table are pretty reactive.

Not all of them burst into flames. But sometimes they corrode, start to fall apart.
So Sanat crosses out another 38 elements, because they're too reactive.

Then we ask him about those two weird rows at the bottom of the table. They're always broken out separately from the main table, and they have some great names — promethium, einsteinium.
But it turns out they're radioactive — put some einsteinium in your pocket, and a year later, you'll be dead....MORE
HT: Professor Mankiw for the title and the link.