1. The Periodic Table and Periodic Law

2. I. Development of the Periodic Table A.Why organize the elements? - Allows us to see underlying patterns - Helps to unify scientific knowledge B. Antoine Lavoisier (1743-1794) -Considered to be the father of modern chemistry -Wrote the first extensive list of elements

3. I. Development of the Periodic Table C. Johann Dobereiner (1780-1849) - Noted chemical similarities in several groups of three elements – what later became known as triads. Included: -chlorine, bromine, and iodine -sulfur, selenium, and tellurium -calcium, strontium, and barium -lithium, sodium, and potassium

4. I. Development of the Periodic Table D. John Newlands (1837-1898) - Noted a connection between the chemical properties of elements and their atomic masses. - When the elements were arranged by increasing atomic mass, every eighth element had similar properties. -Called this the law of octaves.

5. I. Development of the Periodic Table E. Lothar Meyer - Developed a table of elements that further inferred a repeating pattern of properties. F. Dmitri Mendeleev -Independently created a table of elements arranged by increasing atomic mass. -Accounted for discrepancies of earlier tables. -Predicted properties of yet to be discovered elements.

6. I. Development of the Periodic Table G. Henry Moseley - Arranged the table by increasing atomic number. -This made corrected some inconsistencies with Mendeleev’s table. -This is essentially the table that we use today. H. Glenn Seaborg -Instrumental in developing many of the non- naturally occurring elements on the periodic table.

7. II. Reading the Periodic Table A.Periods - Horizontal rows - Metals on the left/Nonmetals on the right - Atomic number increases by 1 as you move to the right.

8. II. Reading the Periodic Table B. Groups or Families - The vertical columns on the periodic table. - For the most part, elements in the same family have similar properties.

9. II. Reading the Periodic Table C. The periodic table and electronic structure 1. Location of the final electrons in each element. a. s block -groups 1 and 2 b. p block -groups 13-18 c. d block - groups 3-12 (Valley of Mystery or the transition metals) d. f block - bottom two rows.

10. II. Reading the Periodic Table 2. Electronic Structure and Location - The location of the elements on the periodic table hints at its electron configuration. - Elements in the same family have the same ending electron configuration, with the exception of the principle energy level. ex: O  2p 4 S  3p 4

12. III. Groups of Elements A.Alkali Metals 1. Location -Group 1 (Li, Na, K, Rb, Cs, Fr) 2. Properties -Soft, shiny, metallic, react with water to form Hydrogen gas.