Electrical conductivity of liquid metals

The dimensionless value $\lambda = 150 (М/\rho)^{1/3}/r$, (M is the molar mass, $\rho$ is density, and r is the specific resistance in $\mu\Omega\cdot$cm), interpreted as the ratio of the mean length of the free range of electrons to the distance between the ions, is examined. A simple formula is found which describes the dependence of $\lambda$ on temperature and pressure through the dependence on density $(\rho) :\lambda = const\cdot \rho^2/(\rho_0-\rho)$, where $\rho_0$ is a parameter. It is shown that the discovered formula is suitable for describing the electrical conductivity of liquid and solid metals in a broad range of states.