The fact that this book is organized according to these basic categories will give you the ability to focus on each topic to whatever degree you feel necessary: if you know you're weak on gas law questions, take extra time going through "The States of Matter" section, for example. Also, each question in the practice tests at the back of this book has been categorized according to these eight categories so you can precisely identify your weaknesses and then concentrate on the areas you need to study most.