1. Chemical Bonds

2. 8 Chemical Bond I want you to meet a friend of mine?s
Chemical
Bond 8
Bonding, the way atoms are attracted to each other to form molecules, determines nearly all of the chemical properties we see. And, as we know, the number “8” is very important to chemical bonding.
I want you to meet a friend of mine?

3. Pure Substances- COMPOUNDS
What is a compound?
2 or more elements chemically bound together
BONDS

4. We will Cover 3 Types of Chemical Bonds
Ionic
Covalent
Metallic

5. Why Bonds Form

6. BONDS Bonds form between elements to become stable atoms….
It’s all about the valence electrons baby!

7. OCTET RULE –Special # 8!!!!
Which group has 8 valence electrons?
What is that group called?
How do they act?

8. OCTET RULE –Special # 8!!!!
Elements want to be like the Noble Gases STABLE…
Elements need full valence shells to feel happy (STABLE)
they want 8 (like the noble gases)
Atoms will Get as close to 8 valence e- as possible by forming bonds

9. How do they do it? How do they get
those valence shells full?
Making bonds with other elements…

10. IONIC BOND bond formed between cation(+) and anion(-) Electrons: transferred from one element to another Let’s see how it happens….

12. Ionic Compounds
Compounds formed by Ionic Bonds-attraction between opposite charges
Always have at least 1 metal
Neutral charge + equal -
Very Strong Bonds
High Melting Point
They Conduct Electricity
Why do you think they do this??

13. Ionic Bonds (Compounds) Elements try to get 8e- in their valence shell
METALS will give up electrons and become cations(+)
Most NON-METALS take/gain electrons
Become anions(-)

14. Polyatomic Ions
A compound (group of atoms) with a charge- this ion sticks together and can bond with other ions
Ex: CO3 has -2 charge
Ex: NH4 has a +1 charge
Polyatomic = Poly (many) Atomic (atoms)

15. Now, on your periodic table you are going to write the Charge (oxidation) Numbers above the Groups – what ion they normally form We call the charge number the Oxidation Number………..

16. Oxidation Number-tells you what charge the element has when it becomes an ion

17. Ionic Bond Rules Your compound must be neutral (balanced)
Make 5 different compounds (ionic bonds)
Cation always goes first, Anion goes after
Polyatomic ions carry 1 charge for the group
Your compounds may only contain 1 type of positive ion and 1 type of negative
See example sheet
Show me what you have made, then draw these on your sheet

18. Chemical Bonds

19. COVALENT BOND Bond between non metals/metalloids bond formed by the sharing of electrons

20. Covalent Bonds

21. Covalent Compounds Compounds formed by SHARING ELECTRONS
Non-metals and/or metalloids only
Weaker Bonds
Low Melting Point
Do not Conduct Electricity
Why do you think they don’t conduct?

22. Bonding and the elements in GROUP 14 …..
Elements with 4 valence electrons only SHARE their valence electrons.

23. Ionic or Covalent?
MgBr2
SiO4
CO2
CoF
H2O
NaCl

24. METALLIC BOND bond between metals

25. Formed between atoms of metallic elements
Metallic Bond
Formed between atoms of metallic elements
Good conductors at all states, lustrous, very high melting points
Examples; Na, Fe, Al, Au, Co

26. In Summary
Atoms bond to become stable (they lose, gain or share electrons)