1. Unit 2 lecture 2- Periodic Table Intro
Why do we have a Periodic Table of Elements? 1

2. The Periodic Table- organizing the elements2

3. History of the Periodic Table
1829: Dobereiner arranged the elements by mass and identified the halogens (group 7) and noble gases (group 8)
1864: Newlands noticed property patterns and reported the law of octaves (8)
1869: Meyer noticed a relationship between properties and atomic mass
1896: Dmitri Mendeleev (father of the periodic table) arranged elements by atomic mass and properties
1914: Henry Moseley arranged the elements by their atomic number and properties
SUMMARY: First was arranged by ATOMIC MASS, then by ATOMIC NUMBER and PROPERTIES

4. Organizing groups by common properties

5. The periodic table tells us about the elements
Find the Key on your periodic table (it uses sodium)

6. Periods and Groups 7 PERIODS - horizontal rows
18 GROUPS (families)- vertical columns whose elements have similar properties.
There are 8 major groups (1A to 8A)

7. On your new periodic table (that you got today) - Label 8 major Groups Label 7 Periods

8. Transition metals, Lanthanides, and Actinides

9. Add in Transition metals, Lanthanides, and actinides

10. Metals (blue), Nonmetals (yellow), metalloids (pink)

11. Color in metals, non-metals, and metalloids- either outline or use highlighters. Make a KEY

12. Metals On the left side of staircase (most of the elements!)
As you move further to the left and down, there is more metallic character
Conductors of heat and electricity
Malleable (can be hammered into thin sheets)
Ductile (can be pulled into wires)
Lustrous (shiny)
Example: Gold

13. Nonmetals Found on the right side of the staircase.
As you move to the right and up, there is more non- metallic character.
Low boiling points, brittle, dull, good insulators
Example: Sulfur

14. Metalloids/semimetals -
Found along the staircase.
Have properties of metals and non-metals
Tend to be good semiconductors in transistors.
Example: Silicon

15. Metallic and non-metallic character

16. Groups with Special Names:
Group 1 (1A) Alkali Metals – soft metals that are extremely reactive.
Group 2 (2A) Alkali Earth Metals – shiny
reactive metals
-Group 17 (7A) Halogens - Extremely reactive nonmetals
- Group 18 (8A) Noble Gases - Inert gases (unreactive with other elements).

17. Add in the four groups with special names

18. You have 10 minutes to complete this task…
Characterize the elements (silicon, lead, carbon, and tin) as metals, non-metals, or metalloids. State which of their properties are like those of metals (look at your lecture notes). For each of the elements give:
symbol, group #, row, if it’s a metal, non-metal or metalloid.