Lol, I attained 100 for my chemistry Half-yearly,
I go to james ruse btw,
So what you can do is read your textbook, see if you understand everything from those two topics. If you can't simply than, find that dot point and write a short summary in your own words.
Once your write those summary for the dotpoints you don't know, try to memorize them. Truse me, it works when your in the exam situition, everything starts to your memory much quuckly.
Don't waste your time now, lol
Just go and study hard!
good luck in your exam, in my school 20 people got 100 in chemistry.... the rest got above 90, so there is a huge competition there, compared to your school. You shoudl't stress too much. Work hard, this is the key