Chapter 7 Sec. 1-4 Ionic Compounds and Metals NOTES

Sec. 1 Ion Formation
o Chemical Bond:

3 Types of Chemical Bonds
 (1) Ionic
 (2) Covalent
o Nonpolar
o Polar
 (3) Metallic
o Valence Electrons
 Determine the chemical properties of an element
 Electrons in the outermost energy level (s & p orbitals)
 Involved in the formation of chemical bonds
 GOAL OF BONDING:
o Positive Ion (Cation) Formation
o Negative Ion (Anion) Formation

Sec. 2 Ionic Bonds and Ionic Compounds
o Ionic Compound:

Examples of Ionic Compounds:
 Formula Unit – simplest formula for an ionic compound
o Ionic Bond:
o Properties of Ionic Compounds
 Ions are packed into a regular repeating pattern called a crystal lattice (3D geometric
arrangement of ions)
 Balances the forces of attraction and repulsion
 Minimizes potential energy (PE)
 Soluble in water but NOT in a nonpolar liquid
 Conduct electricity when melted or in solution
 Able to form electrolytes
 Electrolyte: an ionic compound whose aqueous solution conducts an electric
current because of its free ions
 Properties linked to the strong nature of the ionic bond:
 Hard crystalline solid
 High melting points (MP)
o WHY?

High boiling points (BP)
o WHY?
o Energy in an Ionic Bond
 In every chemical reaction energy is either absorbed (endothermic – when bonds are
broken) or released (exothermic – when bonds are formed)
 Formation of ionic compounds is always exothermic
o WHY?

Lattice Energy:


Characteristics of Lattice Energy
o Released when an ionic bond forms (negative value)
o Directly related to the (1) size of the ions bonded and the (2) charges of
the ions bonded
o The greater the lattice energy the stronger the attraction between the
ions
 Lattice Energy Trends:
o (1) The smaller the size of the ion the ____________________ the lattice
energy.
o (2) The greater an ion’s charge the _______________________ its lattice
energy.
Sec. 4 Metallic Bonds and the Properties of Metals
o Metallic Bond:


“Sea of Electrons” bond
Delocalized electrons: the outermost electrons (valence electrons) in metals which are
free to move around
o Properties of Metals
 High Melting Points (MP)
 High Boiling Points (BP)
 Malleable
 Ductile
 Good conductors of heat and electricity
 As the number of delocalized electrons increases the hardness and strength of the metal
increases (alkali metals are the softest and the weakest)
 Form alloys
 Alloys:

Why alloys?

2 Types of Alloys:
o (1) Interstitial
 Characteristics:

Examples:
o (2) Substituted/Substitutional
 Characteristics:


Property Review
o IONIC COMPOUNDS
o METALLIC COMPOUNDS
Examples: