See also:

• Science: Chemistry: Elements: Nonmetals  (5)
• Science: Technology: Energy: Hydrogen  (166)

ChemGlobe: Hydrogen - - Electronic, thermal, and steric data along with basic information.

Chemical of the Week: Hydrogen - - Equations for reactions between hydrogen and other substances.

ChemicalElements.com: Hydrogen - - Basic information, atomic structure, and table of isotopes.

EnvironmentalChemistry.com: Hydrogen - - Atomic structure, chemical and physical properties, and table of nuclides.

Especiál Gas Inc.: Hydrogen - - Numeric data, uses, and general information.

Hydrogen - - Data tables and historic information.

Hydrogen - Element #1 by David L. Bergman - - "Contrary to popular belief and portrayal of hydrogen in the Periodic Table of Elementary Particles, single, stand-alone atoms of hydrogen are unstable and do not exist" [PDF.

Hydrogen Energies and Spectrum - - The Bohr model for an electron transition in hydrogen between quantized energy levels with different quantum numbers n yields a photon by emission with quantum energy.

It's Elemental: Hydrogen - - Basic physical and historical information.

LANL: Hydrogen - - Brief reference on the element includes discussion of the sources of hydrogen, its current uses, and potential for new energy applications.

Lenntech: Hydrogen - - Physical data, chemical properties, health and environmental effects.

Visual Elements: Hydrogen - - General and physical information, uses, and key isotopes.

Wikipedia: Hydrogen - - Properties of the element, including its history, applications, and characteristics.