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.
1 A fallacy is so conceived that if an argument exhibits a fallacy, it is probably a bad one, but if the argument exhibits no such violation, it is a good one.  2 Fallacies are mistakes in reasoning that do not seem to be mistakes. 3  Indeed, part of the etymology of the word 'fallacy' comes from the notion of deception.