The cohesive and surface energies of 3d metals show an anomalous behavior since they are minimal in the middle of the 3d series. We show that similar anomalies of magnetic origin also occur for many other 3d systems, e.g. for the solution energies of 3d impurities in noble metals and for their binding energies to vacancies. Based on detailed electronic-structure calculations, we demonstrate that all these anomalies arise from the same physical origin: an increased tendency for magnetism for more isolated configurations, resulting in a gain of exchange energy.