NMT Chemistry 121

Updated 2007-03-21 12:52

Chapter 8

Basic Concepts of Chemical Bonding

8.1 Chemical Bonds, Lewis Symbols and the Octet Rule

Ionic BondElectrostatic Forces that exist between ions of opposite charge. Most Often Ionic Substances result from the interaction of metals on the far left side of the periodic table with the nonmetals on the far right side (excluding group 8A)
Covalent BondSharing of Electrons between two atoms. Examples would be nonmetallic elements interactions with each other.
Metallic BondsMetals such as copper, iron, and aluminum. Each atom in a metal is bonded to several neighboring atoms.
Lewis SymbolsChemical Symbol for the element. Plus dot for each valence electron.
Octet RuleAtoms tend to gain, lose or share electrons until they are surrounded by eight valence electrons.

8.2 Ionic Bonding

Question Answer
+Represents the number had given to an electron.
: Shows that a number has been given an electron.
Question Answer
3s Valence ElectronAnything beyond this electron, the Octet Rule doesn't normally apple.
Lattice EnergyEnergy required to completely separate a mole of a solid ionic compound into its gaseous ions.
EndothermicSeparation of Ions(?) everything is separated inside
ExothermicThe Coming together of ions everything is squished together.
Lattice Energyunder certain arrangements of ions, Lattice energy increases as charges on the ions increase and as their radii decrease.


Question Answer
Bond Polaritydescribe the sharing of electrons between atoms.
Nonpolar covalent bondsIs one in which the electrons are shared equally between two atoms.
Polar Covalent bondone of the atoms exerts a greater attraction for the bonding electrons than the other. If the difference in relative ability to attract electrons is large enough, an ionic bond is formed.
ElectronegativityThe ability of an atom in a molecule to attract electrons to itself.

Chapter 9

Molecular Geometry and Bonding Theories

9.1 Molecular Shapes


Question Answer
Bond AnglesThe Angles made by the lines joining the nuclei of the atoms in the molecule.
VSEPRValence-shell electron-pair repulsion

Bond Angles

Bond AngleShape
120°Trigonal Planar
90° & 120°Trigonal bipyramidal
90° & 90°Octahedral

Derivatives from the ABn Geometries

Tetrahedrals and removing their corners


# of Corners RemovedShape Formed
1Trigonal Pyramidal
#>2If there are only two they must be arrange next to each other, and no special name is given to describe that molecule

9.2 The VSEPR Model