Just what it says in the title really. It's not split up into Unit 1 and Unit 2 - it is alphabetical though. Also, I'd like to point out that these may not be definitions that are guarenteed to get you full marks in the exam - for example, I use the word "light" in the definition of "plane polarised light", but in one exam you had to specify that light was electromagnetic radiation to get all the marks. Stuff like that my occasionally crop up, so in the exam, look to see how many marks are for the definition and try to make as many separate points as there are marks, and don't blame me if my definitions weren't quite as accurate as needed (they are all correct though). If you spot any missing, just comment and I'll endeavour to put them in.