In high school chemistry, the teacher was reviewing what we should remember from lower school about atoms & molecules (single bonds, double bonds, slots available for single atoms of different elements). I asked something like "If the model we were using treats the bonding sites on every atom of every element as equal, but says that some molecules are either rarer than others or not known to occur in nature, doesn't that mean the model is incomplete or incorrect?". She instantly shook her head with annoyance and said sternly "No.".
Every time someone told me: "this is a simplified version to give you a basic understanding and later you will be able to learn more accurate versions" that was tremendously helpful and sometimes it sparked my curiosity and motivated me to look stuff up myself.
I mean we should get ahead of the realisation that it doesn't add up.
This can work with your kids though but I don't know if it can be effectively scaled to a school class. Maybe on a few dedicated play/discovery sessions, not on a regular basis.
Graduation could mean an overthrowing of the known-wrong models. Congratulations, here are the next known-wrong models. Now prove these wrong.