Equations for reactions between hydrogen and other substances.

Basic information, atomic structure, and table of isotopes.

Atomic structure, chemical and physical properties, and table of nuclides.

Numeric data, uses, and general information.

Data tables and historic information.

"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]

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.

Basic physical and historical information.

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

Physical data, chemical properties, health and environmental effects.

General and physical information, uses, and key isotopes.

Properties of the element, including its history, applications, and characteristics.