What electrical property causes an object to conduct electricity very well?

Resistance is the physical property that opposes the flow of electric current. Therefore, a material with very low resistance opposes the current very little, making it an excellent conductor of electricity. The other terms represent entirely different concepts. Reluctance is the opposition to magnetic flux, and capacitance is the ability to store an electric charge. While admittance is the reciprocal of impedance, 'low admittance' would actually mean high impedance, which characterizes a poor conductor.