Even if you don't like chemistry, check out this site. Hazardous Chemical Database Enter your search term. History of Physics Exhibits from the American Institute of Physics Exhibits and Online Source Materials for History of Physics and Allied Fields. Many links to more sites about the history of various topics in physics and to biographical information. Images illustrate the 3D structures of varioous inorganic materials.
Introduction explains the importance of atomic structure.
Site relies heavily on the use of interactive demonstration graphics which, by interacting with them, you actually get a feel for various concepts. Many Physics links above also include astronomical information. Comet Observation Page NASA JPL's Charles Morris provides information on currently visible comets and astronomy of comets. Heavenly Details from the Farmer's Almanac Includes solar and lunar eclipses, full moon dates and names for 9 years. Links to Best Fishing Days and Astrological Timetable.