Atoms consist of a positive nucleus and negative electrons flying around outside it. Electrons closest to the nucleus feel a strong negative-on-positive tug, and the bigger atoms get, the bigger the tug. In really big atoms, electrons whip around at speeds close to the speed of light.

Despite the disreputable company it keeps, bismuth is harmless. In fact, it's medicinal: Doctors prescribe it to soothe ulcers, and it's the 'bis' in hot-pink Pepto-Bismol. Overall, it seems like the most out-of-place element on the periodic table, a gentleman among scoundrels.

Polonium is, frankly, pretty useless, and no country in the world except Russia bothered to refine it by the late 2000s.

Sam Kean Quotes