In its Tales from the Periodic Table series, the Exploratorium museum features a collection of half-hour videos showing how elements combine to form compounds. Try viewing the videos on sodium, hydrogen, and carbon compounds.
Science Spot has links to sites on every chemistry topic you might need.
Lesson Plans and More
PBS has a complete lesson plan and video to teach students about the difference between Compounds and Mixtures. Students will learn that a chemical change is needed to break apart bonds in a compound, but that mixtures can be separated by physical procedures.
Also from PBS is a lesson plan for teaching elementary students about chemical reactions in which two substances combine, form new bonds, and transform into a third substance. Then take a look at this video for teachers about the best ways to teach students about concepts like chemical reactions, as in the formation of rust on a bicycle. It explores student misconceptions about atoms, molecules, compounds and reactions and discusses teaching methods to bring these concepts to life.
The American Chemical Society (ACS) has a wealth of resources for elementary and middle school teachers on a variety of topics. Check out Inquiry In Action for grades 3-6, which features chemistry reviews, lesson plans, molecular animations, and activities. Science Activities For Kids, for grades 3-5, has experiments and hands-on explorations along with lesson plans on chemical reactions. Middle School Chemistry offers complete lesson plans for grades 6-8 on a variety of chemistry topics, including chemical reactions and ionic/covalent bonding.
You'll want to take a look at the ACS site for kids, Adventures in Chemistry, which has sections featuring experiments and the chemistry behind items like gum, glue, soda and braces. For younger students, check out the ABC's of Chemistry where you'll find a poem, a video, and a science activity for each letter of the alphabet.
Jefferson Lab has a wide range of teacher resources including reference materials, hands-on activities, videos, and worksheets for classroom use.
Science Kids has chemistry lesson plans with experiments, designed to teach students chemistry concepts through fun hands-on activities. Take a look at the lesson on polymers, chemical compounds formed from repeating molecule groups.
You're going to love the Museum of Science and Industry's terrific interactive resource called GoReact. Students become virtual chemists, combining atoms to create compounds. As they combine atoms from the periodic table in the Reaction Area, they learn about the properties of elements, the most common chemical compounds, and the practical uses of the compounds they create. More advanced students can combine atoms based on ionic bonds or Lewis dots. Can be used as an individual or whole-class activity.
ionic and covalent bonds are demonstrated visually by this animated illustration of the ways atoms bond together by sharing or transferring electrons.
Take a look at the interactive video on compounds and mixtures on the BBC Bitesize site. Kids will enjoy the sound effects when they try to create and break chemical bonds. An online quiz is included.
Check out this teachers' site dedicated to chemical formulas, full of interactive worksheets, tutorials, and online puzzles, games and quizzes for students in grades 5 and up. Designed to help students with naming compounds, writing formulas, understanding ionic bonds, and getting to know the periodic table.
Learn Chemistry, the education website of Britain's Royal Society of Chemistry, has a collection of videos for teachers that demonstrate ways to teach chemistry to elementary students, with emphasis on chemistry in everyday life. Includes handouts and tutorials.