1. The Periodic Table Understanding the Periodic Table of Elements

3. Mendeleev: Discovered a set of patterns that helped him organize Repeating Order Metals, Metalloids, Non-Metals *Except for Hydrogen* Elements are made of only One kind of Atom  Symbols have either one or two letters  The first letter of each symbol is a capital letter  The second letter is a lowercase letter

4. What is the Periodic Table? a table of the chemical elements in which the elements are arranged by order of increasing Atomic Number, which is also the # of protons Horizontal Rows – Periods (7) Vertical Columns – Groups (18) can also be called “Families” An element’s properties can be predicted from its location in the periodic table

5. Groups Periods Elements in the same Group have similar properties Elements in the same Periods have the same # of orbitals

6. Reading the Periodic Table

7. Atomic Number = # of protons = # of electrons Atomic Mass = # of protons + # of neutrons Atomic #Mass ## of Protons# of Neutrons 2654 25 56