In grade 6, all instruction is based on a set of simple learning goals designed to provide a foundation for secondary studies. Each of them is written with a core concept in mind. For skills, the course is meant to provide a hands-on experience with the tools of science and an emphasis on learning lab safety.
The curriculum in grades 7 and 8 leads to the NYS assessment at the end of grade 8. (See http://www.nysedregents.org/Grade8/Science/home.html
Taken together, the two years are a survey of life science, earth science, and physical science, with basic material that previews and sets the stage for high school-level courses in biology, earth science, chemistry, and physics.