Consists of the element's computational data, uses and general information.

Contains rudimentary information and details on the element's atomic structure.

Provides fundamental and physical information of the element's sources and uses.

Contains details on atomic structure, chemical, and physical properties of the element.

Provides physical and historical information about the halogen element.

Gives out physical data, chemical properties, and details on health and environmental effects of the element.

Extensive data on the history, applications, abundance, and properties of the element.