Memorising is the stupidest thing ever for anything other than quotes/names of things. Sure, you might get decent marks, but you're going to do a lot better if you actually LEARN (learning at school? what kind of madness is this!?!) what you're doing, rather than just swallowing the textbook and puking it onto the page during an exam.
For example, there's a bunch of people in my grade who go home and just read parts of the physics textbook until they can remember it all. These people get decent marks, especially for the long response-type questions but when it comes to actually applying the concepts in a scenario that isn't explicitly referenced in the syllabus/textbook they get screwed over and then complain when I beat them after doing much less "study".
This is good advice. Don't memorize - learn. Huge difference. If you go for the memorization technique, when you get to uni you'll probably bomb out, bad.
Example of learning vs. memorising:
In bio I learnt about 4 body systems: digestive, excretory, circulatory and respiratory. Now, I could have just memorized every name and process without actually understanding/learning why it works the way it works. A lot of people obviously did this in their night-before cram, and only just managed to pass.
I, however, spent perhaps 1 hour a week going over what we'd been taught about body systems, not only writing up my study notes, but creating practice exams that I knew would be twice to three times as hard than the real exam would be. Why on earth would I put myself through that? Well, this is the difference between learning and memorizing. The exams I created for myself were very application-based; I'd say "Describe the purposes and processes involved with the excretory system and name all organs involved". Sure, there is a little memorization there, but to actually be able to describe
why and
how your kidneys work, that's another skill entirely.
This is what you need to do in chem and physics.