You know something's amiss when you set off the radiation alarms while walking in to the nuclear power plant. Featured above: A caption for the featured image. Show Notes This is one of those episodes I only got out the door late on Sunday night, so please excuse the mess around here until I can clean things up a bit!   Episode Script Radon is one of the noble gases; thus, its valence shell is full and it's nearly entirely unreactive. But that doesn't make it safe. Quite the opposite, actually. While radon hangs on to its electrons tightly, it's prone to spontaneously ejecting bits of its nucleus as alpha radiation -- and as we've recently learned, that stuff can kill you. So if radon is noble, it's distinctly a Prince-of-Denmark kind of nobility -- a fittingly dramatic way to cap off period 6 and Poisoner's Corridor. You’re listening to The Episodic Table Of Elements, and I’m T. R. Appleton. Each episode, we take a look at the fascinating true stories behind one element on the periodic table. Today, we'll pluck radon from thin air. Even among the weird radioactive elements near the bottom of the periodic table, radon stands out in its oddness. Many of the upcoming elements are laboratory curiosities, often existing only for brief moments in time, with no place in the natural world. Some of them have changed the course of history, but only after humanity found ways to exploit them. Conversely, radon is everywhere on Earth, and it always has been. In minuscule amounts, granted, but the entire time, it's been exercising influence over us and all known life from the very beginning. We really started from the bottom: as single-celled prokaryotes hovering near hydrothermal vents on the sea floor. Now we here: trillions of cells acting in concert to metabolize, locomote, and wear every single chain, even when we're in the house. Every step of that journey was driven by genetic mutation -- slight changes to our DNA, the blueprints to our bodies. Sometimes these cause disabilities, or cancers, but once in a great while, that slight tweak to its DNA will benefit an organism, making it more likely to survive and pass that DNA down to the next generation. The accumulation and development of these changes over time is what we call "evolution." When the subject comes up, most of the focus tends to be on the changes. That makes sense, that's where all the interesting stuff happens, the results of those genetic mutations. But the causes of those mutations are just as critical. Mutations can occur spontaneously, through sexual reproduction or errors in DNA replication, but if that were the only thing driving evolution, the process would be even slower than it already is. Plenty of chemicals can have an effect on DNA molecules when ingested, from cadmium to polycyclic aromatic hydrocarbons. But mutagens aren't only chemical in nature. Bacteria and viruses can alter DNA, and so can ultraviolet light, x-rays, and even cosmic rays from distant stars. You may have noticed those last three are all types of radiation, and the alpha radiation emitted by radon is quite capable of doing the same thing. Whenever polonium decays into lead, bismuth, thallium, etc., that all tends to happen in one place. Those elements are usually solids, so they're not exactly mobile. But when an unstable atom decays into radon, it's freed from its earthly shackles and can float off into the atmosphere. Around sea level, there's pretty reliably about 2,500 atoms of radon per cubic inch. That's out of the many quintillions of atoms occupying that cubic inch -- it's an infinitesimal amount of radon that we're talking about, but it is a pretty constant level and it's pretty well dispersed around the globe.