Inelastic resonance scattering of hot electrons is the fundamental mechanism underlying many electron-stimulated f-sec processes such as desorption or dissociation of molecules adsorbed on metal surfaces. The hot electrons may be produced by an ultrafast laser pulse or by a solid state tunnel device ("slow nanostructure"). Theoretical reaction rates or yields are given as an integral product of the energy distribution of the flux of incident hot electrons with the the inelastic electron scattering cross section (which contains the influence of the fs intra molecular dynamics). For fixed laser fluence, the temporally narrowest pulses produce the hottest electrons. The flux of laser-generated hot electrons incident upon the surface is given by an electron-temperature-dependent expression that is akin to the oldtime Richardson equation for thermionic emission. The all important consequences of this fundamental quantum statistical mechanical constraint on our current understanding of the so-called two-temperature model of DIMET (M=Multiple) will be discussed in detail. In contrast, the incident electron flux produced by the tunnel device may be given by the (again oldtime) Fowler Nordheim equation for field emission. In either case, what is important is the energy of the incident electron relative to the energy level position of the acceptor/LUMO/negative-ion resonance of the reactant. But this is exactly one of the fundamental problems in both hardcore electrochemistry and its contemporary embodiments. Implications of the full circle linkage between venerable electron emission/electrochemistry and ultra-modern Surface Femtochemistry will also be visited.