#francium

Na & K looks exactly the same irl. They are both soft greyish metal that oxidizes quickly upon air contact. If you mix em' up it's gonna be hard to tell them apart.

They have very similar chemical properties, to the point they are almost interchangeable in most reactions. Like in all the mnemonic I've memorized in school, they are right next to each other. E.g. electronegativity, reactivity, precipitation.

Na & K smushed together forms an alloy/amalgam called NaK (duh) which is a liquid. It's cool as hell

In biology, cells would pump their ions so that Na+ is more concentrated outside and K+ inside. Being able to selectively let them pass on demand is how your body can do cool stuff like transmitting neural signals, muscle contraction, and regulate heartbeat.

They both have symbols that don't match their English name, which is rare

I mean Potassium literally lives one floor below Sodium on the table. That's a classic setup in all fiction come on

Salted fried banana is goated food