1. Ch. 12 Chemical Bonding pp. 309-323

2. Structure of Atom Nucleus  Proton –Positive Charge Neutron-No Charge
Electron Cloud  Electron
(Negative Charge)

5. Each Element has a different Atomic Structure consisting of a specific number of Protons, Neutrons, and Electrons
The number and arrangement of Electrons in the Electron Cloud determines the Physical and Chemical Properties of the Element

6. A Chemical Change is the result of a Chemical Bond
Chemical Bond – joining of Atoms to form new substances
H H O = Water
H20

7. By Losing Electrons By Gaining Electrons By Sharing Electrons
4 Ways To Form Bonds
By Losing Electrons
By Gaining Electrons
By Sharing Electrons
By Pooling Electrons

8. How Do You Find Number Electrons
Number of Electrons in an Atom can be determined from the Atomic Number
If Atom has No Charge, then the Atomic Number will be equal to number of Electrons

9. Electron Organization
Electrons in an Atom are organized in Energy Levels within Electron Cloud
Each Energy Level represents a different amount of energy
Each Energy Level can hold a specific number of Electrons

10. The farther an Energy Level is from the Nucleus, the more electrons it can hold
Electrons in the First Energy Level have the lowest amount of Energy
Electrons in the Fourth Energy Level have the highest amount of Energy

11. Energy Level 1 = 2 Electrons

12. Valence Electrons Used to form Chemical Bonds
Electrons in the outermost Energy Level
Used to form Chemical Bonds
Within a Group, the Atoms have the same number of Valence Electrons

13. To Bond or Not To Bond Not all Atoms bond the same way
Group 18 (Noble Gases) will not form bonds

14. -- Exceptions are Hydrogen and Helium (only need 2 Valence Electrons)
Goal  Have a full outermost energy level (valence)
-- 8 Valence Electrons
-- Exceptions are Hydrogen and Helium
(only need 2 Valence Electrons)

15. Noble Gases (Group 18) -- already have 8 Valence Electrons
Halogens (Group 17) -- have 7 Valence Electrons and needs 1 more to stable
Alkali Metals (Group 1) -- have 1 Valence Electron but needs 7 more to be stable
-- it is easier to lose 1 than gain 7

16. Ionic Bonds
Bond that forms when Electrons are transferred from one Atom to another, which results in a positive ion and a negative ion
(opposite charged ions that attract each other)

17. Ion Formed by Losing, Gaining, Sharing, or Pooling Electrons
Atom that is no longer neutral because it has gained or lost an Electron
Formed by Losing, Gaining, Sharing, or Pooling Electrons

18. Forming Positive Ions More Protons than Electrons
Metal Atoms tend loss Electrons
Takes small amount of energy to remove Electrons from atoms in elements from the Alkali Metals (Groups 1) and Alkaline Earth Metals (Groups 2)

19. Forming Negative Ions More Electrons than Protons
Nonmetal Atoms tend gain Electrons
The more easily an Atom gains Electrons, the more energy the Atom releases

20. *CATION-when an atom gives up an electron to another atom and has a positive charge.
*ANION-when an atom gains an electron and has a negative charge.

21. Ionic Compound
Ionic Bonds form when the number of electrons lost by the Metal Atoms equals the number gained by the non-metal atoms
The Ions that Bond are charged, but the compound is Neutral (They Cancel Each Other Out)

22. Ionic Compound When Ions Bond, they form repeating
3-D patterns called a Crystal Lattice
Strong attraction between Ions gives the following properties: brittleness, high melting points, & high boiling points

23. Electron Dot Diagram
Chemical symbol for an Element, surrounded by as many dots as there are Electrons in its outer energy level
Dots are written on the four sides of the symbol and each dot represents a single Electron

24. Electron Dot Diagram
Start by writing one dot on the right of the Element symbol, then add dots to the left, top, and bottom

25. Covalent Bond
Forms when Atoms share one or more pairs of Electrons
Low Melting Points, Low Solubility, low boiling points, brittle in solid state
Most of the things you see everyday (Water, Sugar, Oxygen, Wood)

26. * Single Covalent Bond- when two valence electrons are shared by two atoms.
* Double Covalent Bond- when four valence electrons are shared by two atoms.

27. When 2 Atoms of Non-Metals Bond, a large amount of Energy is needed to either Atom to lose an Electron (so they will share Electrons)
Substances containing Covalent Bonds consist of individual particles called Molecules

28. Simplest Molecules
Diatomic Molecules – Molecules made up of 2 Atoms
Diatomic Elements – Elements found in Nature as Diatomic Molecules
(Oxygen, Nitrogen, Fluorine, Chlorine, Bromine, Iodine)

29. Metallic Bonds What gives Metals their properties
Bond formed by the attraction between positively charged Metal Ions and the Electrons around them
What gives Metals their properties
(Malleable, Ductile, Conduct Electricity)
--because the outermost energy level overlaps, they can bond in different directions