Dimitri Mendeleev discovered that elements when arranged by mass seemed to organize themselves in other ways as well.

How does this periodic table differ from the one displayed in our room?

Metals Nonmetals

 Main (Representative), Transition metals, lanthanides and actinides (rare earth)

 Nonmetals, Metals, Metalloids, Noble gases

 Periods: Are arranged horizontally across the periodic table (rows 1-7)  These elements have the same number of valence shells. 2nd Period 6th Period

 Family: Are arranged vertically down the periodic table (columns or group, or 1-8 A,B)  These elements have the same number electrons in the outer most shells, the valence shell. Alkali Family: 1 e- in the valence shell Alkali Family: 1 e- in the valence shell Halogen Family: 7 e- in the valence shell Halogen Family: 7 e- in the valence shell

 Notable families of the Periodic Table and some important members: Alkal i Alkalin e (earth) Transition Metals Noble Gas HalogenChalcogens