The rungs are composed of hydrogen bonded paired Nitrogenous Bases. These pairings are Adenine to Thymine and Guanine to Cytosine.
A basic definition of an ionic compound is that they are molecules that consist of charged ions. These ions have opposite (both negative and positive) charges. On the other hand, covalent compounds are non-metals which are bound together, and consist of two electrons that are shared between two atoms.
