Chapter : Chemical Bonding Cartoon courtesy of NearingZero.net

Chemical Bonds Lect1 Forces that hold groups of atoms together and make them function as a unit. Ionic bonds – transfer of electrons Metal + Nonmetal Ex) NaCl Li2O Covalent bonds – sharing of electrons. 2 nonmetals Ex) CH4 CO2 Metallic bonds- electrons are free to move throughout the material. Metals

Covalent Bonding Molecule- is the smallest unit quanitity of matter which can exist by itself and retain all the properties of the original substance. When a compound is formed by sharing electrons, the compound is called a ____Molecule__________________ Examples H2O & O2 Diatomic molecule- is a molecule containing 2 identical atoms. (H2 N2 O2 F2 Cl2 Br2 I2) H NO F

Covalent Bonding Diatomic molecule- is a molecule containing 2 identical atoms. (H2 N2 O2 F2 Cl2 Br2 I2) H NO F

Naming Covalent Compounds Two words, with prefixes Prefixes tell you how many. 1-mono, 6- hexa 2-di, 7- hepta (greek) septa (latin) 3-tri, 8-octa 4-tetra, 9-nona 5-penta, 10- deca

Naming Covalent Compounds First element whole name with the appropriate prefix, except mono Second element, -ide ending with appropriate prefix Practice

Electornegativity Lecture 3

Is it Covalent or ionic Nonpolar-Covalent bonds (H2) Electrons are equally shared Electronegativity difference of 0 to 0.5 Polar-Covalent bonds (HCl) Electrons are unequally shared Electronegativity difference between .5 and 2.1 3. Ionic Bonds 2.1- 3.3

Using Electronegativity differences CO 3.5-2.5= 1.0 polar covalent C=2.5 look on table pg 198 O= 3.5 2.1 thru 3.3= Ionic Bond

Electronegativity Nonpolar Covalent Polar covalent Ionic 0-------------0.5 --------------------------------------- >2.1 ---------3.3

practice NaCl Na=0.9 Cl=3.2 3.2-0.9=2.3 NaCl is ionic CO 3.4- 2.6= 0.8 Polar covalent CH4 2.6 -2.2= 0.4 Non polar covalent