Where is sodium on the periodic table of elements?

Sodium is located in Group IA of the Periodic Table mostly because of its electron configuration. All elements in this group have one electron in the outer orbital of its atom (the s-orbital). This link gives information on each element of the periodic table: http://chemistry.about.com/library/blper5.htm To the left is another interesting link about the development of the periodic table (historically), why it looks the way it does, and how position of an element in the table is determined.