Constants, formulae and tablesDescription: Resources that feature unchanging numerical values, facts or principles expressed in mathematical symbols, and/or quantitative information presented in tabular form.
A - F|G - M|N - R|S - Z|#
- Conversion of Units
Institute of Chemistry converters for units, temperatures and currency.
Do integrals via the web
- International critical tables of numerical data, physics, chemistry, and technology
Contains data on physical, thermodynamic, mechanical, and other key properties. Many tables have been "knovelized" to be interactive. Full text of original print version available in PDF format (full-text searchable), including original index. ... 
- International tables for crystallography, vol. A-G
"The series comprises articles and tables of data relevant to crystallographic research and to applications of crystallographic methods in all sciences concerned with the structure and properties of materials. Emphasis is given to symmetry, diffraction methods and techniques of crystal structure determination, and the physical and chemical properties of crystals. Each volume also contains discussions of theory, practical explanations and examples, all of which are useful for teaching."--Home page ... 
Collection of cross-searchable e-books on engineering topics drawn from dozens of technical publishers and professional societies. Includes professional handbooks and analytical tools. ... 
- Knovel critical tables
kCT is a brand new reference featuring tables of properties for commonly used chemical compounds in the physical properties tables. kCT has expanded the original 6,000 chemical compounds in the physical properties tables of International Critical Table. Using multiple sources, kCT contains the most up-to-date chemical properties information available online. ... 
Unit and base conversion as well as an extensive library of units and constants
- NIST chemistry webbook
Provides thermochemical, thermophysical, and ion energetics data compiled by NIST under the Standard Reference Data Program.
- NIST Reference on Constants, Units, and Uncertainty
Addresses three topics: fundamental physical constants, the International System of Units (SI), which is the modern metric system, and expressing the uncertainty of measurement results. ... 
- Smithsonian physical tables (9th revised ed.)
Comprising 901 tables concentrating on a broad scope of common physical and chemical data, the information provided is of general interest to scientists and engineers and of particular interest to those involved with physics in its larger sense. On knovel, the Smithsonian physical tables are now easy to navigate and are full-text searchable. All entries in the index are hyperlinked to their page numbers. ... 
- Thermochemistry of the chemical substances
This reference is a revision of the table of values for the heats of formation in the thermochemistry section in International Critical Tables. It includes 5,840 values of heats of formation and 350 values of heats of transition, fusion, vaporization, and reaction. All entries in the index are hyperlinked to their page numbers. ...