1. Unit 5 – The Periodic Table & Chemical Bonding

2. Objective 1
Identify the position of groups, periods, and different chemical families on the periodic table.

3. Periodic Table Dmitri Mendeleev – mid 1800’s
Proposed a table for 70 elements based on mass and properties
Henry Moseley – 1913
Determined the atomic number of elements and arranged the table in order of atomic number

4. How is the periodic table of elements arranged?
Periods: Rows of the periodic table
Groups: Columns of the periodic table
Periodic Law: When elements are arranged in order of increasing atomic
number, there is a periodic
repetition of their chemical
and physical properties.

5. Groupings to know on the Periodic Table (Fill in on your notes.)
Elements (H, He)
Metals
Non-metals
Metalloids
Transition Metals
Lanthinides
Actinides
Alkali Metals
Alkaline Earth Metals
Halogens
Noble (inert) gases

6. Properties of Metals Metals: Bright metallic luster
Solids are easily deformed
Good conductors of electricity and heat

7. Properties of Nonmetals
Non-lustrous, various colors
Solids may be hard or soft, usually brittle
Poor conductors of electricity

8. Properties of Metalloids
Metalloids have properties intermediate between metals and nonmetals.

9. Objective 2
Identify forces between atoms.

10. Bonding & Reactions The main goal of chemical bonding
and reacting is to fill the outermost
energy level.
Called the octet rule. (8
electrons in the outermost shell,
EXCEPT H, He, Li, Be, which only
need 2.)

11. Two Types of Bonds
1.) Ionic 2.) Covalent
Brain Pop: Chemical Bonds

12. Ionic Bonds Electrons are transferred from one atom to another.
A metal ion with a positive charge sticks to a nonmetal ion with a negative charge.

13. Covalent Bonds Non-metals share electrons to fill outer shells.
Nonmetals like to gain electrons. Since they all want to gain, they must share.

14. Practice: Ionic or Covalent
Practice: Ionic or Covalent? (Metal + Nonmetal = Ionic Nonmetal + Nonmetal = Covalent)
Compound
Metal + Nonmetal or
Nonmetal + Nonmetal?
Ionic or Covalent?
NaCl
H2O2
C6H12O6
MgF2
Al2O3
CO2 O2
Li3P

15. Objective 3
Diagram compounds with Lewis dot structures.

16. Lewis Dot Structures Review
Show valence electrons.
Look at the group number. This is how many dots you draw for each atom.
Ex:
Chlorine Hydrogen
Calcium Helium (Think carefully here!)

17. Lewis Dot Structures: Ionic Bonds
Ions: an atom that has extra or missing electrons
Metals lose their outer electrons, becoming positive.
Na Be Al
Nonmetals gain electrons in their outer shell, becoming negative.
N O Cl

18. Where do these gained or lost electrons go?
Ex: Sodium chloride
Metal = sodium nonmetal = chlorine
Ex: Magnesium oxide
Metal = magnesium nonmetal = oxygen

19. Use the valence electrons!
To find the charge of an ion, look at the valence electrons and count how many they need to give away or add to reach a full energy level (8 electrons for most. 2 electrons for H, He, Li, Be)
Ex: What charge will the following ions have?
sodium magnesium
phosphorous carbon
bromine sulfur

20. Balanced Compound Formula
Forming the compound
The compound is balanced by crossing charges, reducing if possible.
Metal
Charge
Nonmetal
Balanced Compound Formula Li + C = Mg F K O Al P
Brain Pop: Ions

21. Lewis Dot Structures Practice: Ionic Bonds
CaCl2 MgBr2 NaCl Na2O

22. Lewis Dot Structures: Covalent Bonds
Non-metals share electrons to fill outer shells.
1 bond = 2 electrons, 2 bonds = 4 electrons, 3 bonds = 6 electrons
Follow these rules: (Ex: NCl3)
1.) Look at the formula. Then add up total valence electrons needed.
2.) Single bond all of the atoms, picking a center atom when possible. (H is never in the middle.)
3.) Fill every atoms energy level. Remember, most need 8 electrons, but H only needs 2.
4.) Count the electrons & erase some if you have too many. Move the electrons into double or triple bonds if needed.

23. Lewis Dot Structures Practice: Covalent Bonds
N2 Cl2O2 CI4 CBr4