Molecular Monday: Worldbuilding with Lithium

Once upon a time, long before I knew much about chemistry, I wrote a Sci-Fi story set on a moon orbiting some far-flung gas giant. For story reasons, I needed this moon to have some sort of valuable resource, and I picked lithium to be that resource. Again, I didn’t know much about chemistry at the time, but for some reason I guessed this lithium-rich moon would probably have a rust-red color to it, like Mars.

Fast forward to today. I’m currently in the process of revising this and other stories in the Tomorrow News Network series. One of the things I’m trying to do is apply a little more science to my storytelling. And regarding this rust-red moon, it turns out I sort of got this one right!

There is a compound of lithium and nitrogen called lithium nitride (chemical formula Li₃N) which has the kind of dark red color that I wanted for my moon. Lithium nitride forms spontaneously wherever pure lithium comes into contact with atmospheric nitrogen, so it’s fairly easy to make. It doesn’t seem like much of a stretch to me that a lithium-rich moon would be covered in this stuff.

Of course the characters in my story need an otherwise Earth-like environment. That means Earth-like gravity, free oxygen, an active water cycle…

Okay, I’m not clear on just how rapidly everything would catch on fire in this situation, but based on a YouTube demonstration and some lab safety info I found online, it seems you should be careful about exposing lithium nitride to oxygen, and for God’s sake keep it away from water!

So yeah… it seems I have some to rethinking to do. Fortunately, there are other, less explosive lithium compounds I could work with.

Programming note: I’ve been doing Molecular Mondays as a once-per-month thing for a while now, but I feel like I’m starting to slip with my chemistry research. So Molecular Mondays will now return to its original biweekly schedule. So tune in two weeks from today when we’ll be talking about… I don’t know, probably lithium again.