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

3. http://www.chem.msu.su/eng/misc/mendeleev/welcome.html How does this periodic table differ from the one displayed in our room?

4. Metals Nonmetals

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

6.  Nonmetals, Metals, Metalloids, Noble gases

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

8.  Family: Are arranged vertically down the periodic table (columns or group, 1- 18 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

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