1. How do you know how many valence electrons an atom has?
Q of the Day
How do you know how many valence electrons an atom has?
Day

2. Lewis Dot Structures
Notation used to show an abbreviated version of an elements valence electron arrangement H F O

3. H F O Lewis Dot Structures
Notation used to show an abbreviated version of an elements valence electron arrangement H F
 First determine number of valence electrons.
 Valence electrons are represented with dots around the element’s symbol. O

4. H F O Lewis Dot Structures
Notation used to show an abbreviated version of an elements valence electron arrangement H F
 2 e-s. can fit per side (you can think of each side of the symbol as an orbital) O

5. In order to bond an element must be able to give AND take an electron.
Lewis Dot Structures H
In order to bond an element must be able to give AND take an electron. F O

6. Lewis Dot Structures
In order for a bond to form an atom must be able to “give” an electron and “take one” F H
Both can bond once

7. Lewis Dot Structures Examples: Sodium =  can bond ____
Phosphorous =  can bond ____
Aluminum =  can bond ____
Fluorine =  can bond ____

8. Lewis Dot Structures

9. Lewis Dot Structures

10. Lewis Dot Structures
Suggested Steps:
1. Do each individual Lewis dot structure and determine how many times each element can bond
2. Look for ways to make everyone happy
3. Lewis dot structure must match formula!!!

11. Lewis Dot Structures B. Practice: potassium and fluorine bond
magnesium and chlorine bond
lithium and oxygen bond
hydrogen and oxygen bond

12. READ section 7.1 and complete #s 1-8 on page 199 Due Friday 3-27
Assignment
READ section 7.1 and complete #s 1-8 on page 199
Due Friday 3-27
BINDERS!!! 33 12

13. Q of the Day
The halogens all have __ valence which means they all want to ______________.
Day 7
gain one electron

14. How do elements combine to form compounds?
Objective
How do elements combine to form compounds?

15. Electrostatic Force – an interaction between charged particles
Ionic Bonding
Electrostatic Force – an interaction between charged particles 33
Opposites –
Like charges –
Attract
Repel 15

16. Valence electrons dictate reactivity!
Bonding Introduction
What happens when atoms collide?
Valence electrons interact.
Valence electrons dictate reactivity!

17. Opposites Attract!!! Bonding Introduction Holding it all together
Chemical bond – A mutual electrical attraction between the nuclei and valence electrons of different atoms that binds them together … electrostatic force
Nuclei = _______________ charge
positive
Electrons = _______________ charge
negative
Opposites Attract!!!

18. Bonding Introduction
But Why Bond at all?
Atoms want a full set of valence electrons (8) and they can share (bond) to get them!!!
~ octet rule

19. Br Why bonds and ions? Achieving electrical and energetic stability.
Bonding Introduction
Why bonds and ions? Achieving electrical and energetic stability.
Electron pairs – stable - Good
Lone electrons – high potential energy - BAD Br

20. 3 main bond types: Ionic Polar covalent Nonpolar covalent
Bonding Introduction
3 main bond types:
Ionic
Polar covalent
Nonpolar covalent

21. Electrostatic Force – an interaction between charged particles
Ionic Bonding
Electrostatic Force – an interaction between charged particles 33
Opposites –
Like charges –
Attract
Repel 21

22. Ions – charged particles
Ionic Bonding
Ions – charged particles
Cation – positive ion
Anion – negative ion

23. Ionic Bonding
Collision – Ions
(-) Br Li
BANG Br
(+) Li

24. But they don’t separate … WHY?
Ionic Bonding
But they don’t separate … WHY? + - Li Br Li
Electrostatic Force
BANG Br

25. Ionic Bonding
Ionic bonds – Chemical bonds that result from the electrical attraction between large numbers of cations and anions
Cation – ?
Anion – ?

26. Electronegativity – measure of atom’s ability to attract electrons
Ionic Bonding
Atoms Only transfer elecs. (form ions) when one atom has a very strong attraction for elecs. (wants them a lot more)
Electronegativity
Electronegativity – measure of atom’s ability to attract electrons

27. Ionic bonds most commonly form between metals and nonmetals!
Ionic Bonding
Electronegativity P. T. (page 181)
Ionic bonds most commonly form between metals and nonmetals!

28. Ionic bonds are made up of charged pieces (ions)
Ionic Bonding
Ionic bonds are made up of charged pieces (ions)
Ions can be made up of one element or a combination of elements (polyatomic ions)

29. high melting points – strong bonds
Ionic Bonding
Ionic Compounds:
high melting points – strong bonds
Brittle
dissolve in water to produce mobile ions – good conductors

30. Draw the Lewis dot structure for chlorine.
Question of the Day
Draw the Lewis dot structure for chlorine.
Day
2. Draw the Lewis dot structure for oxygen – use your notes packet if needed.

31. READ section 7.1 and complete #s 1-8 on page 199 Due Friday 3-27
Assignment
READ section 7.1 and complete #s 1-8 on page 199
Due Friday 3-27
BINDERS!!!
Quarterly Exam = Tuesday 3-31 33 31

32. Ionic Bonding http://www.youtube.com/watch?v=QqjcCvzWwww

33. L A B
Electrostatic Forces 33