If you need free homeschooling curriculum for science, check out these sites. There are courses for biology, physiology, physics, astronomy, and more.
I have traditionally used textbooks for our science curriculum. The first science books I bought for homeschooling were The Usborne Science Encyclopedia and The Kingfisher Science Encyclopedia.
My daughters used these reference books for reading, note-taking, and to create a history timeline. Then we would use the internet to research subjects that they wanted to learn more about.
With that in mind, I've listed many resources here that can provide you with materials and worksheets for a science class or you can use them to supplement your current curriculum.
Video classes for biology, environmental science, and physics.
Teaching materials for your astronomy curriculum.
Astronomy lessons with the Hubble Space Telescope.
Online Astronomy Academy. Earn a free Certificate of Completion.
NASA Kid's Club
Learn about the U.S. and NASA with online games, puzzles, and coloring pages.
Downloadable video lectures for biology, chemistry, and physics. Live online tests with free membership account. Lecture notes available for some courses.
Online games and quizzes for a variety of subjects, such as animal classification and chemical elements.
Word search, games, diagrams, and reading comprehension exercises. Inventions, animals, physics, and health are just some of the topics covered.
Choose your science worksheets by grade and topic.
Worksheets categorized by subject and age group. Designed for ages 5-14.
The Anatomy of an Eye
Virtual online dissection of an eye. Wonderful!
Anatomy of a Frog
Online frog dissection with video, text, and exercises.
Salmonids: In Troubled Waters
Learn all about salmon with this dissection game. Created for grades 6-9.
Supplement your physics curriculum with these fun online games.