Which exam board is it? I got an A* in igcse edexcel chemistry 2 years ago, and am currently finishing exams in A level chemistry, with a predicted grade of A* if you need any help. The best advice I can give is making sure you understand all the topics thoroughly, and then make short summary cards on the topics you’re struggling with, with the essential facts you need to know. There’s no point in just copying out your notes onto flash cards, just summarise them - it’s faster and means you’re processing the information. You’ll find it will just stick in your head!