>All potassium is always radioactive While practically true, this is sufficiently imprecise to bother the more pedantic variety of nerd; for accuracy I therefo

>All potassium is always radioactive While practically true, this is sufficiently imprecise to bother the more pedantic variety of nerd; for accuracy I therefore quote the relevant section of Wikipedia (a resource we should give daily thanks for): "Naturally occurring potassium is composed of three isotopes, of which potassium-40 is radioactive. Traces of potassium-40 are found in all potassium, and it is the most common radioisotope in the human body."