1. Exploring the Periodic Table
Section 2
Exploring the Periodic Table

2. Learning Targets I can explain why atoms form ions.
I can determine the ion formation of an element. (worksheet)
I can differentiate between nonmetals, metals and metalloids.

3. The Role of Electrons
The periodic trends in the periodic table are the result of electron arrangement
Chemical properties are determined by , which are
Elements in a group have chemical and physical properties in common because they have the same number of
valence electrons
located in the outermost energy level
valence electrons

4. An element’s electron arrangement determines its location in the periodic table

5. Ion Formation

6. Ions What is an ion? An atom with a charge (+ or -)
Why do atoms form ions?
To have a filled outermost energy level
How does an atom become an ion?
Atoms gain or lose e-
What electron configuration does an ion possess?
Electron configurations like noble gases
full shell = stable 

7. Octet Rule
Elements lose, gain, or share electrons to form the required octet in their highest remaining energy level.

8. Ion formation How to make Li look like He? LOSE AN ELECTRON! Li He 3p+

9. Equation of ion formation+ Li
3p+ Li
3p+ +
Li  Li e-
CATION = atom with a POSTIVE charge

10. Ion formation How to make O look like Ne? GAIN 2 ELECTRONS! O Ne 8p+

11. Equation of ion formation2- O
8p+ O
8p+ +
O + 2e-  O2-
ANION = atom with a NEGATIVE charge

12. How are Elements Classified?

14. Metals Most of the elements Shiny Malleable
can be pounded into thin sheets
Conduct heat and electricity
Ductile
can be stretched into thin wires

15. Nonmetals Right side of periodic table Dull Brittle
Poor conductors of heat and electricity (insulators)
Not ductile or malleable
Sulfur
Graphite

16. Semiconductors Metalloids Conduct electricity under certain conditions
Share properties with metals and nonmetals
Ductile and malleable
Solids that can be shiny or dull

17. Learning Target Checkpoint
Why do atoms form ions?
What is the difference between metals, nonmetals and metalloids?