[duskwuff]

> Similarly, I'm guessing the periodic table was removed from the grade 10 book because it's already present in the grade 9 book.

That still doesn't make sense. The periodic table doesn't stop being relevant in 10th grade just because it was introduced in 9th grade.

[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.