This was kind of infuriating about high school chemistry. We were taught so much simply is and that's that. Gold and Mercury differ by one proton, so why is one a dense, yellowish metal and the other one liquid at room temperature? Carbon and Nitrogen sit right next to each other on the periodic table, so why are their chemical properties so different? Why are there so few elements that are ferromagnetic? We dove relatively deep into chemical bonds and isotopes, but glossed over fundamental things like why compounds with similar structures had seemingly random, unrelated properties.