The simple Huckel model of the chemical bond, proposed earlier and applied mostly to homonuclear diatomics, is extended to the case of the heteropolar bond. The filling of electrons into the MO levels has now more possibilities than in the previous homonuclear case. For orthogonal AOs, the fundamental quantities entering the model, the atomic energy difference x(2) - x(1) and the bond integral \beta\ can be determined using the experimental values of the atomization energy D, and the electric dipole moment p. The results obtained for the two-electron sigma-bonds occurring in the first-row series of around state diatomic hydrides are analyzed and shortly discussed. (C) 2003 Elsevier B.V. All rights reserved.