Are you looking for a free Chemistry curriculum for your middle school student? Middle School Chemistry has Free Chemistry Lessons for Middle School Students [1] on their site. This is a full chemistry curriculum which includes experiments, reading, activity sheets, and more. You will find lessons on Density, The Periodic Table, Matter, Changes of State, and more.
Be sure to check out all the free homeschool science resources [2] on How To Homeschool For Free.