0. Warm Up 9/21/17
In your folder, on paper, draw the Lewis Dot structures for the following elements:
Potassium
Silicon
Fluorine
Boron
Chlorine
Argon
Phosphorus

1. Forces

2. What holds our world together?
FORCES
What is a chemical bond?
The force that holds two atoms together

3. Review Why do atoms form chemical bonds? How?
What does it mean when an atom is chemically unstable?
What does the octet rule state?
What subatomic particle is involved in forming chemical bonds?
What is a molecule?
How can the periodic table be used to determine the # of valence electrons?
How can the periodic table be used to determine the # of energy levels?
Most matter is electrically neutral, why?
To become more stable by losing, gaining, or sharing electrons
It does not have a full octet of electrons
The outermost energy level has 8 valence electrons (full shell)
Valence electrons
Two or more elements chemically combined together
Look at the group number
Look at the period number
The # of protons cancels out the # of electrons

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

5. Formation of an Ionic Bond
Ionic Bond (strongest) – b/w a metal and nonmetal that involves a gain or loss of electrons
When an atom loses a valence electron to another atom, it becomes
a (+) ion – CATION
When an atom accepts a valence electron from another atom, it becomes a (-) ion – ANION

6. Na Cl EXAMPLE Metal Non-metal 1 valence e- 7 valence e- Cation – Na +1
Anion – Cl -1

7. They are now attracted to one another because one is positive and
The other negative (opposite charges attract). A bond forms.

8. Na Cl EXAMPLE Metal Non-metal 1 valence e- 7 valence e- Cation – Na +1
Sodium chloride Na Cl
1 valence e-
7 valence e-
Cation – Na +1
Anion – Cl -1

9. Na Cl EXAMPLE Metal Non-metal 1 valence e- 7 valence e- Cation – Li +1
Anion – F -1

10. Potassium Bromide
Magnesium chloride

11. EXAMPLE
Metal
Non-metal Na Cl
Calcium chloride

12. Lewis Dot Structure 2+ 1- DROP AND SWITCH THE CHARGES
Shows the # of valence elecrons the atom has 2+ 1-
What is the charge on Ca?
What is the charge on F?
How many atoms of Ca and F are needed?
DROP AND SWITCH THE CHARGES

13. Drop and Switch
Ca F-
Drop
Ca F1
Switch
CaF2

14. Naming Ionic Bonds-Nomenclature
*Cation is always written first, as it appears on the period table
Then write the Anion changing the suffix (ending) of the anion to -ide

15. Properties of Ionic Compounds
SALTS
Crystals
hard 22oC
high melting point temperatures
nonconductors of electricity in solid phase
good conductors in liquid phase or dissolved in water (aq)
Break apart/dissolve easily in water

16. Metallic Bonds
Valence e- are mobile (move freely among all metal atoms)
Metal to metal bonding

17. 9/26/17
Notes- Covalent Bonds

18. 2 Types of Forces
Intramolecular Force (stronger)bonds between atoms holds elements together to make compounds, ex.)Ionic and Covalent
Intermolecular Force (weaker) holds molecules together to form solids, liquids, and gases, ex.)Hydrogen bond.

19. COVALENT BOND bond formed by the sharing of electrons between nonmetals.

20. Properties of Molecular Substances
Covalent
bonding
Low m.p. temp and b.p. temps
relatively soft solids as compared to ionic compounds
nonconductors of electricity in any phase

21. 2 Types of Covalent Bonds
Polar Covalent Bond – electrons are unevenly shared
Nonpolar Covalent Bond – electrons are evenly shared (diatomics)

22. Non PolarCovalent Bonds
Equal Sharing of electrons
H-H

23. Non Polar Covalent bonds- Two atoms share one or more pairs of outer-shell electrons.
Oxygen Atom
Oxygen Atom
Oxygen Molecule (O2)

24. O O N N DOUBLE bond TRIPLE bond atoms that share two e- pairs (4 e-)
atoms that share three e- pairs (6 e-)
N N

25. when electrons are shared but shared unequally
POLAR COVALENT BONDS
when electrons are shared but shared unequally
H2O

26. Oxygen has the ve- more of the time so it is slightly –
Hydrogen has the ve- less often and is slightly +
- water is a polar molecule because electrons are pulled closer to oxygen.

27. Water is a bent moleculeH H

28. Intermolecular Forces:holds molecules together, weaker force
EX.)Hydrogen Bond – when H bonds to N, O, or F
Important in DNA (genetic material), proteins, and water molecules

29. Hydrogen “Bonding” Strong polar attraction
Like magnets
Occurs ONLY between H of one molecule and N, O, F of another
H “bond”

30. Intermolecular Force – between different molecules
Example: an interstate highway runs between different states

31. Intramolecular Force Intermolecular Force very weak Hydrogen bond
Very strong Covalent bond
Intermolecular Force
very weak Hydrogen bond

32. Water
Intramolecular force
Intermolecular force

33. Nomenclature-naming covalent Compounds