Before 1971, the number of passive electrical components was limited to three: resistor, capacitor, and inductor. In 1971, Pr. Chua predicted the existence of a fourth element, called memristor, since it corresponds to a resistor with memory behavior. Several years later, the concept of memory circuit was extended to capacitors and inductors. This paper proposes mathematical models for mem-elements, validated by Matlab and experimental circuit emulators for memcapacitor and meminductor. The experimental results show a good fit between theory, Ltspice simulations, and emulation circuits.