A chemical formula is a concise list of the elements in a compound and the ratios of these elements. To better understand what a chemical formula means, we must consider how an ionic compound is constructed from its ions.
A fallacy is an incorrect argument in logic and rhetoric. It gives a result which is not valid or lacks soundness. Fallacies are either formal fallacies or informal fallacies.
If we reason by paying too much attention to exceptions to the rule, and generalize on the exceptions, our reasoning contains this fallacy. This fallacy is the converse of the accident fallacy. It is a kind of Hasty Generalization, by generalizing too quickly from a peculiar case.