Here are some links that will help you with your revision.
year 5 learning objectives
End of year Revision sheets
THis is the BBC bitesize website for Key Stage 2. It is split into 3:-
Living things - biology (keeping healthy and life cycles)
Materials - chemistry units (states of matter / gases around us)
physical science - physics units (THe Earth and beyond / sound)
This web site might also be useful. look down the list to find the topic you are after.