Chemistry

1. Use practice questions to help revise.

2. For organic chemistry - keep re-writing mechanisms regularly because they're not something you want to have to relearn every time you have a test.

3. Use Youtube videos to help you understand topics before the lesson.

"Physics and maths tutor" - plenty of practice questions on there - https://www.physicsandmathstutor.com/

"Chemguide" - lots of notes on all the topics in the course - https://www.chemguide.co.uk/

"Quizlet" - for definitions of keywords and short answered questions - https://quizlet.com/en-gb

"A Level CGP Chemistry Textbook" - this isn't an online resource, but some students bought this themselves.