[nkmnz]

The way chemistry is taught in schools isn't very logic in a lot of ways – it's based on heuristics. It's mostly some empirical rules, but if feels like you have more exceptions from those rules than real applications. The reasons are that 1) each molecule is a complex and complicated quantum mechanical system and 2) each observable unit of chemistry (one or more substances and their transitions in reactions or change of state) is a thermodynamic system with complex statistics. Highschoolers - not unlike alchemists - lack the math to describe these problems, so they are taught heuristics that are useful in understand a lot (but not all) everyday-chemistry.