1. Chemical BONDING

2. Chemical Bond
A bond results from the attraction of nuclei for electrons
All atoms trying to achieve a stable octet

3. Two Major Types of Bonding
Ionic Bonding
one atom has a stronger attraction for electrons than the other.
“steals” an electron from a second atom
Covalent Bonding
In covalent bonding the attraction for electrons is similar for two atoms.
They share their electrons to obtain an octet.

4. IONic Bonding
electrons are transferred between valence shells of atoms
ionic compounds are
made of ions
NOT MOLECULES
ionic compounds are called Salts or Crystals

5. [METALS ]+ [NON-METALS ]-
IONic bonding
Always formed between metals and non-metals
[METALS ]+ [NON-METALS ]-
Lost e-
Gained e-

6. Covalent Bonding Pairs of e- are shared between non-metal atoms
molecules
Pairs of e- are shared between non-metal atoms

7. 4 Steps for determining Chemical Bonds
1. Is it a Metal or Non-metal?

8. 4 Steps for determining Chemical Bonds
Determine if the bond is covalent or ionic.
Covalent
IONIC
Non-metal + Non-metal
Metal +
Non-metal

9. 4 Steps for determining Chemical Bonds
Determine the number of valance electrons for each element.
Can be found easily by looking at the group number on the periodic table

10. 4 Steps for determining Chemical Bonds
Draw the Lewis Structure for each element

11. 4 Steps for determining Chemical Bonds
Now you are ready to create the bond between elements.
If the elements are forming a covalent bond they will be sharing electrons and have no charge

12. 4 Steps for determining Chemical Bonds
IF the elements are IONIC they will be giving or taking an electron from the outershell and will have a positive or negative charge.

13. Ions An ion is a charged atom
Positive ion- an atom that loses one or more electrons ion a transfer
Negative Ion- an atom that gains an electron from the transfer.
NaF
MgCl
AlCl

14. Ionic bonding Ionic bonding involves 3 steps (3 energies)
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Ionic bonding involves 3 steps (3 energies)
loss of an electron(s) by one element
gain of electron(s) by a second element
attraction between positive and negative e– 1) 2) Na Cl 3)
Cl–
Na+
Cl–
Na+

15. Ionic bonding ( Li + Cl)
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Ionic bonding (stealing/transfer of electrons) can be represented in three different ways
3p+
4n0
2e-
17p+
18n0
8e-8e-2e
3p+
4n0
2e-1e-
17p+
18n0
7e- 8e- 2e-
1e- Li Cl
[ Cl ]–
[Li]+

16. Ionic bonding: Mg + O Mg + O  [Mg]2+[O]2– O Mg [ O ]2– [Mg]2+ 1e- 1e-
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Mg + O  [Mg]2+[O]2–
12p+
12n0
2e- 8e- 2e-
6e- 2e-
8n0
8p+
8e- 2e-
8n0
8p+
1e-
12p+
12n0
2e- 8e-
1e- O Mg
[ O ]2–
[Mg]2+

17. Ionic bonding: Al + Cl Al + 3Cl [Al]3+[Cl]3– Cl Al Cl [ Cl ]3– [Al]3+
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Al + 3Cl [Al]3+[Cl]3– Cl Al Cl
[ Cl ]3–
[Al]3+ Cl

18. Now you try with NaCl

19. [Na]+ [ Cl ]- NaCl This is the finished Lewis Dot Structure
How did we get here?

20. Always remember atoms are trying to complete their outer shell!
The number of electrons the atoms needs is the total number of bonds they can make.
Ex. … H? O? F? N? Cl? C?
one two one three one four

21. Try another one: Methane CH4

22. Methane CH4 This is the finished Lewis dot structure
How did we get here?

23. What did the atom of fluorine
say to the atom of
sodium?
You complete me.