In an RC circuit, it is inversely related to frequency.  
In the s-domain, an inductor with no initial conditions can be characterized as having this quantity of s times the inductance.  In an RLC circuit, this quantity is at a minimum at the resonance frequency. In an RC circuit, it is inversely related to frequency.  In Thevenin's theorem for AC circuits, a circuit can be replaced by a single voltage source and a single value of this quantity. In a purely capacitive circuit it is equal to the total capacitive reactance.  One may combine values of this in series by adding the two complex forms.  Reactance is the imaginary part of this.  For 10 points, name this quantity that for a pure resistor is resistance, the opposition of a circuit to AC, written as Z.
In the s-domain, an inductor with no initial conditions can be characterized as having this quantity of s times the inductance.  
electrical impedance [or complex impedance]