BONDING TYPES ctnd.

What is covalent bonding?What is metallic bonding?

How do you name or write covalent compounds?

BONDING TYPES

• Ionic stealing, transfer of electrons• Covalent sharing of electrons• Metallic bonds are attractions of floating

valence e- to other positively charged cations (Sea of electrons, drifter)

Watch Video: Common Types of Atomic Bondshttp://aaronfreeman.wikispaces.com/file/view/Common_Types_of_Atomic_Bonds.mov

Ionic or Covalent?

• How can I easily determine if a substance is ionic or covalent?

• By calculating difference in electronegativity! • Rule of Thumb – Magic Number = 1.67• If the difference is > 1.67 IONIC

< 1.67 COVALENT

= 1.67 50% Ionic and 50% Covalent

ELECTRONEGATIVITY VALUES

EXAMPLES• EX. Examine electronegativity between F and Cs

F = 4.0 Cs = .7|4.0 - .7| = 3.3 so …. IONIC COMPOUND

Practice• Ca and Cl Ca = 1.0 Cl = 3.0• Difference is 2.0 so Ionic Compound

• S and O S = 2.5 O = 3.5

• Difference is 1 so Covalent Compound

COVALENT COMPOUNDS • Molecules neutral group of atoms held together

by covalent bonds

• Molecular/Covalent Compounds compound whose simplest units are molecules

• Low melting/boiling points• Made from two nonmetals

• EX. H2O water CO2 carbon monoxide

MOLECULES

MOLECULAR FORMULA

• Molecular Formula chemical formula of covalent cmpd

• Actual number of atoms in each molecule

• Does NOT tell us about arrangement of atoms

• H2O : 2 atoms of H 1

atom of O• C2H6 : 2 atoms of C

6 atoms of H

NAMING MOLECULAR COMPOUNDS

• DO NOT USE CHARGES!!!!

• USE PREFIXES AND SUFFIXES tells how many atoms of each element are present in each molecule of the compound

• How would you name?CO2 or SO3

Carbon Dioxide Sulfur Trioxide

NAMING MOLECULAR COMPOUNDSIf covalent: use prefixes• OMIT the prefix mono- if the first atom is = 1 p.269• ADD suffix to the second element of –ide

• SF6

• Cl2O8

• SO3

• ICl4

• P2O5

• Carbon Tetraiodide• Phosphorus Trichloride• Dinitrogen Trioxide• Br2 I2 O2

Sulfur Hexafluoride

Dichlorine Octoxygen …. NOT Octa-oxygen

Sulfur Trioxide

Iodine Tetrachloride

Diphosphorus Pentoxide … NOT Penta-oxide

CI4

PCl3

N2O3

Bromine Iodine Oxygen