1. Overview of the Periodic Table

2.  First periodic table- 1869  Elements were originally arranged in rows by ATOMIC MASS  He noticed that when arranged by atomic masses, the elements’ properties started repeating regularly.  He arranged elements in columns by properties

3.  Moseley fixed some of the problems in Mendeleev’s table.  1913, he rearranged Mendeleev’s periodic table, basing it on ATOMIC NUMBER and VALENCE ELECTRON CONFIGURATION, not atomic mass.

4.  When elements are arranged in order of increasing atomic number, there is a periodic pattern in their physical and chemical properties.  So, let’s see how this all works …

6.  GROUP / FAMILY: vertical columns  PERIOD / SERIES: horizontal rows  Labeling Groups (18 groups) ◦ European System: 1A, 2A, 3A, 4A……1B, 2B, 3B…. ◦ U.S. System: 1A, 2A, 3B, 4B, 5B……1B, 2B, 3A, 4A, 5A… ◦ IUPAC: 1985 decided on #1-18

7. http://www.chem4kids.com/files/elem_pertable.html Rows are called “Periods” There are 7 PERIODS Elements in the same period are different from each other Moves from Metals (left) to Nonmetals (right) Valence electron shells (outermost energy levels) fill up as elements move from left to right

8.  Inner Transition Metals ◦ Lanthanide Series (57) and Actinide Series (89) placed below to keep the size of the table manageable

9. http://www.chem4kids.com/files/elem_pertable.html Columns are called “Groups” Elements in a group have the same number of valence electrons. 1st group has one valence electron (s 1 ), 2 nd group has two valence electrons (s 2 ) Groups have similar chemical properties, due to the fact that they have the same number of valence electrons

11.  Main-group elements, also known as Representative Elements  These “represent” the outer energy level arrangements (s & p sublevels)  These are comprised of the s block & p block

12.  How does the organization of the periodic table indicate …  … how an element is classified? and  … how an element interacts with other elements?