1. The Periodic Table

2. What Does Periodic Mean?
Periodic means repeated in a pattern
Think about a calendar:
Weeks are periodic – they repeat every 7 days

3. Dimitri Mendeleev ( )
Created the first way to organize all known elements
Based his table on the pattern of chemical properties

4. Mendeleev’s Periodic Table
Based on chemical properties
Organized by atomic masses
Predicted unknown elements

6. Henry Moseley (1887 – 1915)
His work led to a reorganization of Mendeleev’s table by atomic number
Killed by a sniper in World War One at age 27

7. The Modern Periodic Table
Organized into
Rows = Periods
Columns = Families

8. Periods and Families
The families are numbered at the top of your periodic table in your reference table
Take a pen and number the periods
Number one is the row with Hydrogen
Number seven is the row with Francium

9. Names of Families
Group
1A or 1
Alkali Metals

10. Names of Families
Group
2A or 2
Alkaline Earth Metals

11. Names of Families
Group
7A or 17
Halogens

12. Names of Families
Group
8A or 18
Noble Gasses

13. Special Groups
Groups
3-12
Transition Metals

14. Special Groups
1st Row at Bottom
Lanthanoids OR
Lanthanides

15. Special Groups
2nd Row at Bottom
Actinoids OR
Actinides

16. One Other Feature Notice the dark stairstep line.
Separates metals from nonmetals

18. Metals To the left of the stair-step line
Typically solids with high melting points
Good conductors of heat and electricity
Malleable – can be formed into a different shape
Ductile – can be drawn into wires

19. Metals
As you move left across the periodic table, metals become more reactive
As you move down a group (family), metals become more reactive
Remember the video about cesium?
Where are the most reactive elements on the periodic table?

20. Metalloids Touching the stair-step line
Have properties in between metals and nonmetals
Semiconductors – Think silicon in computer chips

21. Nonmetals To the right of the stair-step line
Typically gasses with low melting points
Very poor conductors of heat and electricity
Brittle – break rather than change shape

22. Nonmetals
As you move right across the periodic table, nonmetals become more reactive
As you move down a group (family), nonmetals become less reactive
Where are the most reactive nonmetals?

23. Exit Ticket On the index card, please answer the following questions:
Which group is the halogens?
What is the most reactive non-metal?
What is the most reactive metal?
List two metalloids.