This is probably a very rookie question but I'm trying to understand chemical reactions better. I understand how to write down the equations and solve them but now I'm wondering how to tell if any reaction at all will occur. Long story short, I'm trying to figure out how I can tell if and how two random chemicals will bond. I don't expect an actual answer to my question but if someone could tell me what topic to research so I can understand it, I'd be grateful.
I understand that if I put Na and Cl together, they'll form table salt. I understand they'll do this because Na has 1 valence electron and Cl has 7, etc etc.
But what about chemicals like Sulfur and Oxygen? These do bind and form SO2, but how can I tell that that's what they do? They both have 6 valence electrons so I understand that they can "covalently" share those 2 electrons to fill their outer shell, but what's the rule that tells me that they do this?
I keep being given chemicals and told to explain what the end results are. But how do I know that they will react at all? There must be some rule that says Chemical X and Chemical Y will interact to form a molecule, or dissociate, or oxidize or something. I have to believe there is some law or set of laws that will let me figure out if two chemicals will interact and if so under what circumstances (tempreture, pressure, etc). If you have to learn every single reaction between 2 chemicals by rote, the science of chemistry would seem to be impossible to learn.
If anyone could just tell me what area to research to figure this out I'd appreciate it, as none of my books even mention the concept.