It's a little hard I would say for anyone under about 6th grade! It came up in material for 2nd grade, and while I like my child to be challenged, this is a bit much! The material is good, but really difficult, and not at all what I was expecting.
This is very challenging material but written in a way that makes it interesting. It has an easy to follow style and is organized very well. It is visually a little dull, but this is made up for in the Student Journal which I highly recommend to accompany it. It has a strong foundation in the scientific method and I know it will prepare my child well for future science courses. I really like the experiments so far and how they make use of easy to find supplies.
It was suggested to me by another home schooler that Apologia in the middle grades was too difficult. Not so! The text has an excellent flow, as well as being easily understood by my 11 and 13 year old children.
I will stay in line with Apologia through High school.
Also, no where else have I found prices for books and materials matching those of Christianbook.
This was our first year using Apologia High School Sciences. Our daughter used this text for 8th grade and LOVED it!!! The made the concepts easy to understand and there were lots of hands-on experiments which gave her more insight into how the processes worked.