It is not often realized by chemists that the special theory of relativity is behind several aspects of quantum chemistry. The Schrdinger equation itself is based on relations between space-time and energy-momentum four vectors. Electron spin is, of course, the most obvious manifestation of relativity. The chemistry of some heavy elements is influenced by relativistic effects, for example, the nobility of gold and the liquidity of mercury. A relativistic argument can be invoked to explain away the existence of nodes in wavefunctions. This article is an attempt to present these effects on a purely qualitative level, accessible even to first-year college students. Other issues that this article touches on include the existence of antimatter and the relativistic particle-in-a-box problem.