Hi there! I took the HESI for Chamberlain about a month ago now. The topics they test are Math, English, Chemistry, Biology, and last Anatomy & Physiology then they do a personality profile (that is not graded it just pinpoints like your personality traits). I studied three weeks for 30 minutes a night and passed just fine the 1st try. The Hesi is taken from an outside company that asks questions from a database so no matter what state your in if they take the Hesi it uses the exact test format.
I did not personally find the HESI book that Chamberlain suggests - I think it's evolve? I read from other HESI takers to pick up the McGraw Hill brand study guide and I am GLAD I did! It is much better organized! I did all the practice tests over and over again and it definitely prepared me for the test.
The Chemistry section
They asked about ions protons neutrons basic definitions listed in the book
Know how to solve the questions in the study books AND Metric conversions. They are going to be basic conversions - I looked online for metric conversion tests online and those prepared me just find.. grams to milligram's, meters to kilometers, like basic stuff cups, pints, gallons and so on
I found that it was worth it to study the online study guides (I did Google searches for it) and found that many vocab words were on the test.. they will give you a sentence and ask you the meaning of the underlined word.. the underlined word though, doesn't always tend to be something you recognize and it's Not always easy to guess. I highly suggest you take the vocab section in the book serious.
I am NOT a test person or a math person and I passed and got into Chamberlain first time.