[Bekknqv]

Right, but the goal here is to reduce the burden by removing things that are already present elsewhere.

You could probably make the same argument for a bunch of other 9th grade topics.

Regardless, teachers won't just pretend like the periodic table doesn't exist though, they'll talk about it in 10th grade too, because it ties into a few other chapters, but the key difference is that the students won't be graded on it in their final exams.