2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/22706We determine the wavefunctions of electrons bound to a positively charged mesoscopic metallic cluster covered by an insulating surface layer. The radius of the metal core and the thickness of the insulating surface layer are of the order of a couple of angstroems. We study in particular the electromagnetic decay of externally located electrons into unoccupied internally located states which exhibits a resonance behaviour. This resonance structure has the consequence that the lifetime of the `mesoscopic atoms' may vary by up to 6 orders of magnitude depending on the values of the parameters (from sec to years).39 pages and 12 figuresMesoscale and Nanoscale Physicstext