As far as i know the science sc tests every topic that you have studied since the beginning of year 9. I assume that every school does the same topics so they would be:
Year 9
Health and Disease
Electrical Energy
Natural Events (so tsunamis, plate tectonics etc)
Atoms and Elements
Waves
The human body (reproduction, dna, etc)
Year 10
Machines and the laws of motion
The history of Everything (this is what they called it at our school....its just the big bang and the universe combined with evolution and natural selection)
Compounds and Reactions
Ecosystems, Resources and Technology
Looking at past sc papers there also seems to be quite a bit about experiments and stuff, so know how to design fair experiments, what independant and dependant variables are etc.