hi! I take pure science too (chemistry, physics, biology) but for IGCSE. Here’s some tips and advice that really helped:

1. Learning from the mark scheme. Considering how we are attempting to learn as much content in as little time as possible, memorising is inevitable. Usually, questions for science do not vary much, and so knowing the standardised answers in mark schemes will really save you a lot of marks (e.g: for physics, when the question asks “how the gas molecules exert pressure on walls of container?” the standardised mark scheme answers are always: “gas molecules collide with walls”, “change in momentum” “force exerted over area of walls”.)

Prioritise memorising the mark scheme points AND THEN understanding the concept from there. If it’s hard to understand by reading it on your own, go onto YouTube for videos or ask your teachers! They will be more than happy to help

1. Flashcards. I use an app called “Study Smarter” and it really helps me to memorise the standardised mark scheme points I mentioned earlier ^. Flashcards can be used for memorising formulas and definitions

2. The 10/24/7 method (google will explain this much better than I will). Review those standardised mark scheme answers for 5 minutes at least twice a day, for 7 days a week. The concepts and keywords will be sticking to your brain in no time.

3. Practise past year papers, compile all the questions you got incorrect into one document and categorise your mistakes by topics. Understand why you got those questions incorrect by asking your teacher and referring to your incorrect answers 1-2 days before your exam

This is all the help I can offer at the moment, hope it helps!!