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.
The term is preferred as logic is the use of valid reasoning and a fallacy is an argument that uses poor reasoning therefore the term logical fallacy is an oxymoron. However, the same terms are used in informal discourse to mean an argument which is problematic for any reason.