55:29
The halogens
The halogens is the only group that contains elements representing all three familiar states of matter at standard temperature and pressure. Segments in this program include Exploring the Halogens (properties of the halogens); Fluorine: The Painless...
23:47
The periodic table
Much more than a list of elements, the periodic table is a snapshot of how matter is organized on Earth and throughout the universe. Divided into five sections, this program looks at the history and components of the periodic table: The History of t...