Planet Pailly

Welcome back to another edition of Molecular Mondays, a special biweekly series here on Planet Pailly combining two of my least favorite things: chemistry and Mondays.

These past few weeks, I’ve been reading a lot and learning a lot about lithium, because I’m a science fiction writer and I need to know stuff about this particular element for worldbuilding purposes. Except so far, I seem to be doing more world-destroying than worldbuilding.

Lithium is the kind of element that tends to form really strong chemical bonds—so strong that once lithium bonds to other elements, it can be really difficult to make it let go.

In fact Johan Arfwedson, the chemist who discovered lithium, was never able to isolate the element by itself. He could only infer its existence based on the unusually bright crimson color produced when a lithium-containing compound was burned (in other words, he was only able to identify it spectroscopically).

Given how hard it is to isolate lithium, I assumed lithium mining must be an arduous task. And it probably would be if we had to extract it directly from rock; but over three quarters of the world’s commercially available lithium does not come from rock. It comes from brine.

Pockets of water beneath the Earth’s surface can, over long periods of time, leech minerals like lithium out of the surrounding rock. The lithium intermingles with other elements in the water, creating lithium salts, and gradually as the water gets saltier and saltier it turns into lithium brine.

All we have to do is dredge that briny water up out of the ground, pour it into an artificial pool, and leave it out under strong sunlight. When the water part of the brine evaporates away, we’re left with lots and lots of lithium salts (and other kinds of salt too, but for our purposes we only care about the lithium salts). Apparently this is one of the easiest mining processes around, and also one of the least harmful to the environment.

I still have more research to do on this subject, but at least now I know my fictional lithium-rich moon would not necessarily burst into flames just because there’s water.

Welcome back to another edition of Molecular Mondays, a special biweekly series here on Planet Pailly combining two of my least favorite things: chemistry and Mondays.

My current Sci-Fi work in progress is starting to turn into a bigger project than I originally anticipated, which means I need to learn more about lithium: the chemical element which I’ve unwisely scattered all over a certain alien moon.

Over the years, I’ve found that one of the best ways to learn about science (at least for me) is to take a historical approach. With that in mind, today I’d like to talk a little about the moment in history when lithium was first discovered.

It was 1817. Sweedish chemist Johan August Arfwedson was working in the laboratory of Jon Jakob Berzelius, on of the great “fathers of modern chemistry.”

Apparently it was common practice for chemists at that time (and also for chemists today) to light things on fire in order to see what color flames they’d get. Because different materials burn in different colors, the colors can tell you a great deal about what material you’re actually working with. Today this is known as a flame test.

Arfwedson was flame testing a kind of rock called petalite. When burned, petalite produced an intense crimson flame, like this:

Now when Arfwedson saw those bright crimson flames, he did not immediately conclude that he’d discovered a new element. Instead, he did what any good scientist would do: he thought up possible explanations for this crimson color and then systematically tested each possibility, ruling them out one by one.

In the end, Arfwedson was left with only one possibility: petalite must contain a previously unknown alkali metal. Arfwedson named this alkali metal lithium, after the Greek word for stone. “This name,” Berzelius, Arfwedson’s mentor, would later write, “recalls that it was discovered in the mineral kingdom, whereas the two others [sodium and potassium were the only other known alkali metals at the time] have their origin in the vegetable kingdom.”

At this point, you might be wondering what any of this has to do with my story. I’m kind of wondering that myself. Umm… I’ll get back to you about that. In the meantime, there are lots of other cool flame test videos to watch on YouTube.

Sources

Lithium from the Royal Society of Chemistry

Lithium from Elementymology & Elements Multidict

Alkali Metal from the Encyclopedia Britannica

After today’s post, you might never look at a glass of water the same way again.

The water molecule is made of two hydrogen atoms plus one oxygen atom, arranged in a Mickey Mouse shape, with the chemical formula H₂0. You already knew that, I’m sure. But you may not be aware of this: water’s chemical formula gives you a hint about water’s true nature.

Hydrogen ions play an important role in acid/base chemistry, so when you see hydrogen listed first in a chemical formula, that typically indicates that you’re looking at the chemical formula of an acid.

• Acid: an acid is a chemical that can give up a proton (a.k.a. a hydrogen ion) to a base.
• Base: a base is a chemical that can accept a proton from an acid.

Water can do both. It’s an acid. It’s also a base.

• Acidic Water: a water molecule (H₂O) can give up a proton to a base, transforming itself into a hydroxide ion (HO^–).
• Basic Water: a water molecule (H₂O) can accept a proton from an acid, transforming into a molecule called hydronium (H₃O⁺).

Now this is where things get really freaky: because water is both an acid and a base, it can actually react with itself.

Image credit: Manuel Almagro Rivas – Own work, CC BY-SA 4.0, Link

In fact water is constantly reacting with itself. The result is that even “pure water” is really a mix of water, hydroxide, and hydronium in a proton-swapping party that never ends.

Something to think about the next time you drink a glass of water.

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Today’s post is part of a special series here on Planet Pailly called Molecular Mondays.

On the first Monday of the month, we take a closer look at the atoms and molecules that make up our physical universe, both in reality and in science fiction.