- Atomic Spectra Database
One of the over 80 databases accessible through the NIST Data Gateway (see also that entry). This database "contains data for atom and ion transitions, and energy levels. Lines are included for the first 99 elements in the periodic table. The energy level tables also contain ionization limits. ASD contains data on about 950 spectra."
This site states that is a "virtual library of biochemistry, molecular biology and cell biology." It is divided into the following 19 subject pages: angiogenesis, apoptosis, carbohydrates, cell adhesion & ECM, cell cycle, cell senescence, chemical biology, cytoskeleton & motility, development, enzymes, genes, lipids & membranes, metabolism, microscopy, organelles, proteins, signaling, structural biology, and systems biology."
- ChemDex Index - Sheffield
This site is a directory of links to over 5,000 chemistry resources.
- Chemical Education Digital Library
This site is a group of resources, collections, and communities. Resources include: Models 360, Periodic Table Live!, and a Glossary. Collections include: Biographies of Chemists, Featured Molecules, and Living Textbooks. Communities include: Chemistry Laboratories, Inorganic Chemistry, and Physical Chemistry.
This site is produced by the National Library of Medicine and is a database of over "400,000 chemical records, of which over 300,000 include chemical structures, and is searchable by Name, Synonym, CAS Registry Number, Molecular Formula, Classification Code, Locator Code, Structure, Toxicity, and/or Physical properties." It comes in two different versions: Lite and Advanced.
- Chemistry Web Book
One of the over 80 databases accessible through the NIST Data Gateway (see also that entry). This database provides access to thermochemical, thermophysical, and ion energetics data.
- Chemistry: the website of the American Chemical Society
This is the primary ACS site.
This is a free chemical search engine and is owned by the Royal Society of Chemistry. It provides access to information on over 30 million structures and their associated properties.
- Classic Chemistry
The principal purpose of this site is to "post the texts of several classic papers from the history of chemistry." In addition, there are also links to classic calculations, to a history of chemistry calendar, and to glossary of archaic chemical terms.
- Eric Weisstein's World of Chemistry
This site is an online chemistry encyclopedia, which is subdivided into the following categories: Chemical Reactions, Experimental Chemistry, Geology, Inorganic Chemistry, Mineralogy, Organic Chemistry, Petrology, and Quantum Chemistry.
- Hazardous Substances Data Bank
This data file is maintained by the National Institutes of Health and provides access to information on the toxicity of approximately 5,000 chemical substance or mixtures of substances.
This online handbook provides useful information on chemical properties and values.
- Links for Chemists
This site is an index of over 8,400 chemistry resources on the World Wide Web.
- Molecule of the Month
This site features a new molecule each month. The information provided depends on the contributor, but often there is information on the history of molecule and some bibliographic references. After the name of the featured molecule, there are links to five different viewing formats. To view the information on the molecule, click on your preferred viewing format.
- NIST Data Gateway
The National Institute of Standards & Technology (NIST) provides access at this site to over 90 databases of numeric data. These include the Atomic Spectra Database and the Chemistry Web Book (see those entries for more information about these databases). It is possible to search by keyword, property, and substance name.
This site is a free service consisting of three databases: PubChem Compound, PubChem Substance, and PubChem Bio-Assay. They contain information regarding the chemical structures and the biological activities of small organic molecules.
- U.S. Chemical Safety and Hazard Investigation Board
This board is an is an "independent federal agency charged with investigating industrial chemical accidents." This site has links to current and past investigations as well as to the recommendations made as a result of these investigations. There are also a number of safety videos available at this site.
This is the primary site on the World Wide Web for information relating to the periodic table.
- Wired Chemist
This site has four main divisions: Chemistry, Mineralogy, Environmental and NMR. The four divisions are then subdivided into three sections. The Instructional section under Chemistry links to general chemistry lecture notes, tutorials, problem sets, lab exercises, and animated demonstrations.