1. Covalent Bonding

2. Covalent Bond: –a bond formed by the sharing of electrons between atoms. (does NOT form charges) –Made up of nonmetals Molecule: a neutral group of atoms joined together by covalent bonds. (Compounds formed with ionic bonds do NOT have molecules) Molecular Formula: chemical formula for a molecular compound. It shows how many atoms of each element a molecule contains.

3. Covalent Bonding Examples: ascorbic acid (vitamin C): C 6 H 8 O 6 C_____, H_____, O_____, trinitrotoluene (TNT): C 7 H 5 N 3 O 6 C_____, H_____, N_____, O_____, 686 7536

4. Molecular Nomenclature Prefix System (binary compounds) 1.Less electronegative atom comes first. 2.Add prefixes to indicate # of atoms. Omit mono- prefix on first element. 3.Change the ending of the second element to -ide. most

5. PREFIX mono- di- tri- tetra- penta- hexa- hepta- octa- nona- deca- NUMBER 1 2 3 4 5 6 7 8 9 10 Molecular Nomenclature Only use “mono” on the second element.

6. P2O5 =P2O5 =P2O5 =P2O5 = CO 2 = CO = N 2 O = diphosphorus pentoxide carbon dioxide carbon monoxide dinitrogen monoxide Naming Covalent Binary Compounds PCl 5 N2H4N2H4N2H4N2H4 Cl 2 O 7 IO 2 phosphorous pentachloride = dinitrogen tetrahydride = dichlorine heptaoxide = iodine dioxide =

7. Lewis Structures Octet Rule –Most atoms form bonds in order to obtain 8 valence e - –Full energy level stability ~ Noble Gases Ne

8. Bonding Summary IonicCovalent Octet achieved by: Transfer of electrons (forming + & - ions) Sharing electrons Made of: Metal cation (+) & Nonmetal anion (-) Nonmetals (above metalloid line) (no charges) Characteristics: BrittleSmall and very large molecules Structure: Arranged in alternating + & - ions (crystal lattice) Individual molecules Representative Particle: Formula Unit: (lowest whole number ratio of atoms) Molecule: (group of joined atoms)

9. Bonding Summary IonicCovalent Physical State: SolidSolid, Liquid, Gas Melting Point: HighLow Electrical Conductivity: Yes, when dissolved in water or melted No

10. Bonding Summary Metallic Octet achieved by: Valence e- delocalized around metal atoms Made of: Metal cation (+) & Valence electrons Characteristics: Maleable, ductile, lustrous Structure: “Electron Sea” Representative Particle: Atom Metallic Physical State: Solid (except Hg) Melting Point: High Electrical Conductivity: Yes (any form)

11. Ionic Bonding - Crystal Lattice Types of Bonds

12. Covalent Bonding - True Molecules Types of Bonds Diatomic Molecule

13. Metallic Bonding - “Electron Sea” Types of Bonds