1. Chapter 3 Notes: The Periodic Table
Chapter 3.1: The arrangement of elements in the Periodic Table helps to predict their electron configuration.
Chapter 3 Notes: The Periodic Table

2. Periodic Table History
Many scientists worked on how to organize the elements, but Demetri Mendeleyev is credited with making the breakthrough arrangement.
Left gaps to fill in elements that have not been discovered yet.
Had no knowledge of the structure of the atom
Working with properties of elements

3. Periods and Groups Si Ge As Sb Te Po Periods = across (rows)
Groups = down (columns)
Valence electrons related to group number and blocks (s, p, d, f)
Non-metals = right side of “stairs”
Reactive ex: Halogens
Unreactive ex: Noble gases
Metals = left side of “stairs”
Reactive ex: Alkali metals
Metalloids = up and down of “stairs” Si
Ge As
Sb Te Po