If you are homeschooling for any amount of time, you have discovered there is no “perfect” curriculum. Unfortunately, this also applies to the sciences. There are no perfect curricula out there to teach your student any particular science, no magic system where you can just plug it in and the student learns! Every student has his own way of learning, and curricula in general may not cater to that way of learning. As a parent, you must determine which one will suit your student the most and teach him in the most effective way.
In planning your student’s high school studies, it is important for you to give more and more responsibilities not only in chores (or jobs outside the home), but in his schoolwork as well. It is important to get his input as to his preference of when to study biology, physical science, physics or chemistry. (The latter 2 are more important if he is going into a science- related field.) The student needs to learn how to budget his time, how to set goals and how to get through the school year. This is a life-learning objective, something he will use in college and throughout his adult life.
Teaching the student science through the early years was easy and full of fun activities. Now that the student has reached high school, a panic sets in! It is high school now, and science is not supposed to be fun. How is a parent supposed to teach, and make sure the student learns all that a future Einstein should know?
There are plenty of textbooks out there to choose from. The textbook approach is basically to read a chapter and answer the questions at the end. There may be lab activities to do that are suggested in each chapter. This approach will succeed if the student is a visual learner. The challenge presents itself when the student is not a visual learner, but either an auditory and/or kinesthetic learner. The traditional approach, for these students, is far more challenging.
My personal preference is the channelled discovery approach. The planning stage is more time consuming, yet well worth the effort. This is the way that I, personally, learn best. When I search the information out for myself, I tend to REMEMBER and UNDERSTAND the subject at hand.
Chemistry and Physics labs tend to be more involved and potentially overwhelming. Even most textbooks and curricula available in these subjects have labs more suited for the traditional classroom than for the homeschool. Any curricula that you choose, you must bend to fit the student. At the high school level, the parent needs to nudge the student to be more independent and self-motivated, to help the student to learn which way he learns best, and how to overcome any shortfalls. This will help him the rest of his life. The goal is to prepare your student to meet life with as much wisdom, knowledge and understanding as possible. You CAN do this!