The alloying behaviour of liquid amalgams HgNa and HgK is investigated presuming the existence of chemical complexes Hg2Na and Hg2K. This is used to compute the concentration dependence of electrical resistivity and entropy of mixing. The study reveals that the constituent metals of these alloys undergo major structural changes in atomic and electronic character on alloying. A concentration‐dependent anomaly occurs due to preferential ordering of unlike atoms as nearest neighbours.