1. 6-1 ORGANIZING THE ELEMENTS KEY CONCEPTS 1.How did chemists begin to organize the known elements? 2.How did Mendeleev organize his periodic table? 3.How is the modern periodic table organized? 4.What are the three broad classes of elements? MAIN IDEAS 1.Periodic Law 2.Metals 3.Nonmetals 4.Metalloids The way to get started is to quit talking and begin doing. - Walt Disney IaN pg. 19

2. B. Chemists used element properties to sort them into groups. 1. 1829 – J.W. Dobereiner (German Chemist) publishes triad classification system I. Search for Organization A.Only 13 known elements by 1700 1. Isolating them was the key 2. Ancient civilizations aware of some (Cu, Ag, & Au)

3. Two chemists working independently of each other started the work of classifying all the known elements. A. Lothar Meyer, (1830 –1895) a German chemist, Developed an incomplete periodic table in 1869, arranged 56 elements by their atomic weights. 1830 -- 1895 II. Mendeleev’s Periodic Table

4. B. Dmitri Mendeleev, (1834 – 1907), Russian chemist, in 1869 published his periodic table of elements. (BEFORE MEYER DID!) 1. Arranged the 62 elements by their physical and chemical properties and increasing atomic mass. (Prior to known atomic structure!) 1834 -- 1907

5. 2. Mendeleev accurately predicted and left gaps for elements yet to be discovered! (see ?’s) = Ga, Ge and Sc

6. B. Henry Moseley (1887 – 1915), British physicist, in 1913 arranged the modern periodic table by increasing atomic numbers (not mass!). 1887 -- 1915 III. Periodic Law A. Organizing by Atomic Mass = displaced elements.

7. 1. Groups (Columns) = similar properties. Also known as FAMILIES of Elements! 2. Periods (Rows) = similar properties across a period. Pattern repeats from 1 period to the next = PERIODIC LAW or Periodicity!!!

8. IV. Metals, Nonmetals & Metalloids A.Metals = majority of elements (80%) 1. Conduct Heat & Electricity. 2. High luster & Sheen (reflects light) 3. Solid @ normal temp. & pressure (Except Hg) 4. Ductile & most are malleable too.

9. B.Nonmetals = more variation, including Hydrogen! 1. In general = poor conductors of heat & electricity 2. Most gases @ rm. Temp. 3. Few solids = (P, S) brittle 4. 1 Liquid = Br

10. C. Metalloids = properties of metals & nonmetals 1. Dependent upon conditions

11. Blank Periodic Table IaN pg. 18 1. Color code the Metals, Nonmetals & Metalloids. Create a Key!

12. Ticket out the Door Or Homework? Answer questions 24 – 29 on page 181 in your Textbook on a separate sheet of paper.