A database of chemical compounds that also provides "information that a general-purpose WWW index cannot, including physical property data and 2D chemical structures."
Chemistry Central provides access to peer-reviewed open access research in chemistry, from BioMed Central - the leading biomedical open access publisher. This site features chemistry-related articles published in Chemistry Central Journal and independent journals utilizing BioMed Central's open access publishing services.
A ready-reference handbook of the most frequently used data in science, including the periodic table of elements, basic constants and units, and geophysical data.