Compounds of the alkali (oxidation number +1) and alkaline earth metals (oxidation number +2) are typically ionic in nature. Compounds of metals with higher oxidation numbers (e.g., tin +4) tend to form molecular compounds In ionic and covalent molecular compounds usually the less electronegative element is given first. In ionic compounds the names are given which refer to the oxidation (ionic) state In molecular compounds the names are given which refer to the number of molecules present in the compound

on—in which the atoms of one element gain electrons. Consider, for example, the reaction of Cr2+(aq) with manganese dioxide (MnO2) in the presence of dilute acid. Equation 6.2.16.2.1\ref{20.2.1} is the net ion

pH=pKa+log[A−][HA]pH=pKa+log⁡[A−][HA]

−2(aq)⟶CH3