Defined for ionic species B by \(\lambda = |z_{\text{B}}|\ F\ u_{\text{B}}\) where \(z_{\text{B}}\) is the @C00993@ of the ionic species B, \(F\) is the @F02325@, and \(u_{\text{B}}\) is the @E01932@ of species B. In most current practice \(z_{\text{B}}\) is taken as unity, i.e. ionic conductivity is taken as that of species such as Na⁺, Ca²⁺/2, La³⁺/3 etc. To avoid ambiguity the species considered should be clearly stated, e.g. as \(\lambda (\text{Ca}^{\text{2+}}/2)\).