Noble gases—radon, xenon, krypton, argon, neon, and helium—are snobs. Their atoms typically shun liaisons with other elements because they already have all the electrons they need, but none to share.

A version of this story appeared in Volume 85, Issue 40 Although dianions containing a B=B bond have been reported by other groups, no one previously had been able to get two boron atoms to form a ...