The periodic table - classification of elements. Definitions of groups, periods, alkali metals, alkaline earth metals, halogens, and noble gases. How metals, non-metals, and metalloids can be identified by the position on the periodic table. Created by Jay. Introduction to the periodic table. The periodic table - classification of elements. Groups of the periodic table. Counting valence electrons for main group elements.
OPENBook is software developed for blind and visually impaired individuals to read, edit, and manage scanned images from books, magazines, manuals, bills, newspapers, and other printed documents. It essentially turns your computer system into a scanning and reading machine.
GNU/Linux is a free and open source software operating system for computers. The operating system is a collection of the basic instructions that tell the electronic parts of the computer what to do and how to work. Free, Libre and open source software (FLOSS) means that everyone has the freedom to use it, see how it works, and change it.