Think about the way that you revise those and why those sink in. Is it because you're interested in the topics? If so try and work out a way to make science more interesting. If you can't think of any way to do that, then you have to make it 'fun'. Come up with little easy to remember rhymes, or make really colourful mindmaps and notes. Set up a system of how you're going to revise something and stick to it: e.g. writing out definitions with the word itself in one colour and the definition in another.