TPT has a LOT of inaccuracies. The absence of different heat capacities for different pixels, extremely simplified electricity, “unreal” elements such as BIZR, literally the entire “radioactive” tab... The list goes on and on. The best thing vanilla TPT has to offer for homeschooling is a very simplified (but sometimes quite impressive) illustration of some physical and chemical processes.
Not really, there's some simplified chemical reactions and that. The pressure and airflow systems are pretty fun to play around, they're probably the most realistic part but really not scientific.