1. Unit: Chemistry Lesson 2: Organizing the Elements Essential Questions: 1.) What did Mendeleev discover? 2.) What information does the periodic table contain? 3.) How is the periodic table useful?

2. Mendeleev’s Work Properties of elements he studied:  Melting point  Density  Color Average mass of allAtomic mass the isotopes of that element

3.  He arranged the element cards in increasing atomic mass.  A pattern of properties appeared. Textbook page 81

4. An arrangement of Periodic table elements showing the repeating pattern of their properties  The atomic number determines the chemical properties

5. Mendeleev’s Periodic Table In his periodic table, Mendeleev left blank spaces. He predicted that the blank spaces would be filled by elements that had not yet been discovered. He even correctly predicted the properties of those new elements.

6. Information in the Periodic Table 1.) Atomic Number 2.) Chemical Symbol- an abbreviation of the element’s name 3.) Atomic Mass

7. Textbook page 84

8. How is the Periodic Table Useful?  An element’s properties can be predicted from its location.

9. A horizontal rowPeriod of elements. The properties change in a pattern. Elements of Period 3 The properties of the Period 3 elements change as you move across the period. Which of these are Metal? Metalloid? Nonmetal?

10. A column of Group elements. The elements have the same properties. Elements of Group 10 The elements of Group 10 include nickel (Ni), palladium (Pd), platinum (Pt), and darmstadtium (Ds).