NeoK12 has activites and videos about simple machines, including a Bill Nye the Science Guy video. They also have videos, games, and worksheets for many other science topics. This site charges a subscription fee of $24.95 for an individual.
The Museum of Science in Boston has pages that describe simple machines, including a Gadget Anatomy page where you can learn which simple machines are used in some common devices.
Simple Machine Unit by Cindy Downes - Cindy Downes has a unit about simple machines for primary grades.
Discovery Education has a unit study about sound waves.
The Physics Classroom has a unit about sound for older students.
BBC Schools Science Clips has interactive games for younger students about sound and hearing.
PBS Learning Media has video lessons about how light travels, geometric optics, the speed of light, and observing refraction of light.
Ted Ed has lessons about light waves, which include video clips and quizzes.
NeoK12 has short video clips about light.
Learning Ideas - Grades K-8 has instructions for creating an electric circuit. This blog also has other experiments that students in grades K-8 can do to learn about electricity, along with links for a wordsearch and a video about electric circuits.
Education.com has instructions for an experiment to find out how batteries work.
PBS Learning Media has lessons and short videos about electricity.
BBC Bitesize has lessons on electricity. This site also has a glossary, games, and a quiz.
MrCauseysworld.com - Mr Causey, a chemistry teacher for over 30 years, has free resources for chemistry on his website. You can also watch video lessons for chemistry on his Youtube page. He also offers a free mini course about chemistry at yourchemcoach.com.
The Periodic Table of Videos, offered by the University of Nottingham, has links to videos about each of the elements. Click on an element in the periodic table, and you can view a video about that element. These are fun!
Cosmolearning.com has a free online video course for General Chemistry. This course, presented by Rob Lederer (Chemguy) is for Junior High School. Topics included in these lectures are: Compounds, Stoichiometry, Gases, Solutions, Balancing, Chemical Bonding, the Mole and many more. Chemguy also has video courses for Senior Chemistry, AP Chemistry, and Organic Chemistry.
The Periodic Table is an interactive unit for grades 9-12 offered by Interactives.
Balancing Chemical Equations - Jefferson Lab has an interactive page on its site for balancing chemical equations.
Mr. Guch's Cavalcade o' Chemistry has free chemistry worksheets with answers, written tutorials, free labs, and many other free resources for chemistry. Ian Guch is the author of The Complete Idiot's Guide to Chemistry (3rd Edition) .
APlusPhysics.com is a free online physics resource that has video lessons, sample practice problems, and interactive tests.
Bozemanscience.com has a playlist of videos for physics on its Youtube channel. These were created by Paul Andersen.
The Physics Classroom an online interactive tutorial of basic physics concepts. The lessons use an easy-to-understand language to present common physics principles discussed in a first-year high school physics course. There are sample problems and solutions on this site.
HippoCampus offers a physics class online. The animated presentations make the lessons very interesting, even for younger students.
Nova has a page called Physics of Stone Arches to go with their show, Building the Great Cathedrals. The page has a link to a fun interactive activity in which you can try to build a cathedral arch without it collapsing while you learn more about the forces at work in contructing an arch.
Apologia Physical Science Vocabulary Flashcards - Quia and Quizlet flashcards for Apologia Education Ministries' Exploring Creation with Physical Science by Dr. Jay L. Wile