<p>Over the past few decades, the author has developed a theory for atomic liquids. This theory successfully explains the behaviour of viscosity and its temperature dependence, among other properties. This theory considers strong attractions among atoms up to a few atomic distances and accounts for significant temporal disorder. An expression for the coefficient of viscosity (η) and its temperature dependence has been derived for liquid metal. The proposed theory also provides a relation between viscosity and strong atomic attractions over short distances. In this theory, both diffusional and atomic contributions play a role in the transfer of momentum. Initially, the atomic correlation contribution is more significant, but as temperature increases, this contribution decreases while the diffusional contribution increases. In the present work, calculations have been performed for liquid potassium over the temperature range from its melting point (T_m) to its boiling point (T_b). The calculated values of η for liquid potassium within this temperature range show good agreement with the available experimental data, with the highest deviation being 11.4%, which is well within experimental uncertainties.</p>