As far as the Science section getting broken down... there will be questions concerning:
-Human Body Science
There are a total of 30 items, so about 5 questions per category all ranging from easy to medium to hard.
You might want to look into also purchasing the online study guide from ATI. It will give you a print out at the end that looks identical to what you will get at the end of the real test. It also offers some tips on why you missed the problems and how to solve each (I think the paper booklet also does this at the end of each section).
They said when I took the test that pretty much everybody had a low science score, and not to sweat it... and that proved true for me also. My overall grade was an 81- my highest section being an 86 in English and my lowest in Science being a 73.... and I still got in
So don't stress too much. It's not a big deal. This isn't the only thing they look at when considering students and when considering the points scale it amounts to very little (I think my TEAS score gave me something like 6 points).
Each program varies, and the average for mine was a 79, so i was just 2 points higher. But in Feb of this year the national average was a 74.
There will be a total of around 170 questions. I can't really think of anything else to tell you... but again, just don't stress over it. If you're stressed out you won't do as well as if you just walked in thinking, "I got this!" Just know that you don't need to make an A, or B, and if the program average was a C, then I'm sure you can even get in with that