However, physicists use other convenient units as well, e.g., in cgs units, where esu/(cm-sec-K) is used. The Lorentz number, defined as L=κ/σT is a quantity independent of the carrier density and the scattering mechanism. Its value for a gas of non-interacting electrons (typical carriers in good metallic conductors) is 2.72×10 esu/K, or equivalently, 2.44×10 Watt-Ohm/K.