Given an anion X with a charge of -2 that forms an ionic compound with ammonium, determine how many hydrogen atoms are present in a single molecule of the substance.

Covalent bonds generally form when the bonded elements have a difference in electronegativity less than 1.5. subtract the electronegativities for the following pairs of elements and predict whether they form a covalent bond. electronegativity difference of c and c: ionic covalent electronegativity difference of mg and cl: ionic covalent