Question

What is the property of hydrogen chloride that shows its covalent bond? what is the property of MgCl2 that shows its ionic bond?

Answer 1

HCl shows covalent bond because of the difference in the electronegativity of H and Cl atoms this leads to polarity between the atoms .thus there is a sharing of one electron and the bond is covalent.
MgCl2 has an ionic bond because in this transfer of electrons takes place.the 2 chlorine atoms lose their valence electrons while Mg gains those electrons.