1. Bonding

2. Electron Configuration
Remember that electron configuration refers to the arrangement of electrons in the orbital of an atom!

3. Three Types We will study . . . Ionic Bonding Covalent Bonding
Metallic Bonding
occurs between a metal and a nonmetal
occurs between two nonmetals
occurs WITHIN a metal sample

4. Ionic and Covalent Bonding Video Clip

5. Chemical Bonding
Compounds are formed from chemically bound atoms or ions.
Bonding involves only the valence electrons.
When atoms combine we call them molecules.

6. Valence Electrons
Electrons are found in specific orbits/clouds spinning around the nucleus
Valence electrons are the electrons located in the outermost orbit
Elements become stable when:
their outer orbit contains 8 electrons or their outer orbit becomes empty
Lewis Dot Diagrams show the # of Valence Electrons

8. The Octet Rule
When the highest energy level of an atom is filled, the atom is stable.
Atoms tend to gain, lose, or share electrons until they have eight valence electrons.
Hydrogen and Helium are the only exceptions. Because they are so small, they are satisfied with two valence electrons.
Why are the noble gases unreactive?

9. Complete this chart:

10. Lewis Symbols / Electron Dot Diagram
Lewis symbols show the valence electrons as dots arranged around the atomic symbol.
hydrogen:
sodium:
chlorine: H Na Cl
· ·

11. Lewis Dot Diagrams of Selected Elements
Show the number of valence electrons
Lewis Dot Diagrams of Selected Elements
                                                                                                                                                      

12. Oxidation #
An oxidation number indicates how many electrons are lost or gained during the bonding process.
Mg loses 2 electrons so it has an oxidation number of +2
Oxygen gains 2 electrons
so it has an oxidation
number of –2.

13. The periodic table show the common oxidation numbers for groups on the periodic table.

14. = Ionic Bonds – formed when atoms gain or lose electrons.
Ex: Na has 1 valence e- =

15. When Na loses that electron,
its 2nd E.L. becomes full and
stable with 8 e-.
Atoms with an electrical
charge are called ions.

16. Ionization
When an atom loses or gains electrons they become ions – or atoms with an electrical charge.
If an atom LOSES an electron, it becomes an ion with a +1 charge.
If an atom GAINS an electron, it becomes an ion with a –1 charge.

17. Chlorine has 7 valence electrons.
If Cl gains 1 electron, its valence shell will be full and stable.

18. Opposites attract, so…

20. Ionic Bonds Na Cl Cation Anion form between a metal and a nonmetal
form as a result of a transfer of electrons
Na becomes a positive ion =
Cl becomes a negative ion =
Cation means “to go down”
– also think cast off
Anion means “to go up”
Also think accept Na Cl
· ·
Cation
Anion

21. Ions 1. Positively or negatively charged atoms. 2
Ions Positively or negatively charged atoms (Number of protons not equal to the
number of electrons.) 3. Metals – give up electrons to form positive ions.
(example: ) 4. Nonmetals – take in electrons to form
negative ions. (example: )

22. Ionic Bonds
What is the formula for the compound that forms between magnesium and chlorine? Cl
· · Mg
· · Cl
· ·

24. Ionic Compounds
Ionic compounds consist of a lattice of positive and negative ions.

25. Ionic Compounds, Characteristic Properties
High melting points
High boiling points
Conduct electric current when melted and when dissolved in solution
All of these properties are a result of the strong attraction among ions within the crystal lattice

26. Animated Reaction sodium and chlorine
Youtube video of sodium reacting with chlorine

27. Covalent Bonds form between two nonmetal atoms
form as a result of a sharing of electrons

28. Covalent Bonding Most atoms share electrons to gain an octet.
Covalent bonds are formed when e- are shared.

30. Diatomic molecules: – covalently bonded atoms of the same type.
Exs: H Cl F2
I O Br N2

31. Polar Molecules
The type of atoms and their shape determine if a molecule is polar or not
With polar molecules there is an uneven distribution of charge…one atom has a stronger attraction for the electrons than the other
Polar molecules attractions are stronger than nonpolar molecules

32. Polar Covalent Bonding in a water molecule

33. Molecular Compounds, Characteristic Properties
Note the correct name for a compound that contains covalent bonds
Low melting points
Low boiling points
Usually gases or liquids at room temp.
Does not conduct electricity well
May or may not dissolve in water (there are several types of molecular compounds)

34. In GENERAL:
Ionic Bonds–
metal / nonmetal
Covalent Bonds–
2 nonmetals

35. Double Bubble – Compare/Contrast Ionic and Covalent Bonding

36. Double Bubble – Compare/Contrast Ionic and Covalent Bonding