SECTION

7.2 Ionic Bonds and Ionic Compounds

Notes 11 - Ionic Compounds

SECTION

7.2 Ionic Bonds and Ionic Compounds

Formation of an Ionic Bond• The electrostatic force that holds oppositely

charged particles together in an ionic compound is called an ionic bond.

• Compounds that contain ionic bonds are called ionic compounds and binary ionic compounds contain only two different elements a metalliccontain only two different elements—a metallic cation and a nonmetallic anion.

SECTION

7.2 Ionic Bonds and Ionic Compounds

Properties of Ionic Compounds• Positive and negative ions exist in a ratio• Positive and negative ions exist in a ratio

determined by the number of electrons transferred from the metal atom to the non-metal atom.

• The repeating pattern of p g pparticle packing in an ionic compound is called an ionic crystalan ionic crystal.

SECTION

7.2 Ionic Bonds and Ionic Compounds

Properties of Ionic Compounds (cont.)

• The strong attractions among the positive and• The strong attractions among the positive and negative ions result in the formation of the crystal lattice.

• A crystal lattice is the three-dimensional geometric arrangement of particles, and is responsible for theresponsible for the structure of many minerals.

SECTION

7.3 Names and Formulas for Ionic Compounds

Formulas for Ionic Compounds• When writing names and formulas for ionicWhen writing names and formulas for ionic

compounds, the cation appears first followed by the anion.

SECTION

7.3 Names and Formulas for Ionic Compounds

Formulas for Ionic Compounds (cont.)

• A formula unit represents the simplest ratio of the ions involved.

• Monatomic ions are one-atom ions.

SECTION

7.3 Names and Formulas for Ionic Compounds

Formulas for Ionic Compounds (cont.)

• Oxidation number, or oxidation state, is , ,the charge of a monatomic ion.

SECTION

7.3 Names and Formulas for Ionic Compounds

• The symbol for the cation is always written Formulas for Ionic Compounds (cont.)

y yfirst, followed by the symbol of the anion.

• Subscripts represent the number of ions ofSubscripts represent the number of ions of each element in an ionic compound.

• The total charge must equal zero in an ionicThe total charge must equal zero in an ionic compound.

SECTION

7.3 Names and Formulas for Ionic Compounds

Formulas for Ionic Compounds (cont.)

• Polyatomic ions are ions made up of more than one atom.

• Since polyatomic ions exist as a p yunit, never change subscripts of the atoms within the ion. If more than one polyatomic ion isthan one polyatomic ion is needed, place parentheses around the ion and write the appropriate subscript outside the parentheses.

SECTION

7.3 Names and Formulas for Ionic Compounds

Formulas for Ionic Compounds (cont.)

SECTION

7.3 Names and Formulas for Ionic Compounds

• Chemical nomenclature is a systematic way of i d

Names for Ions and Ionic Compounds (Cont.)

naming compounds.– Name the cation followed by the anion.

– For monatomic cations use the element name– For monatomic cations use the element name.

– For monatomic anions, use the root element name and the suffix –ide.

– To distinguish between different oxidation states of the same element, the oxidation state is written in

h f h f h iparentheses after the name of the cation.

– When the compound contains a polyatomic ion, name the cation followed by the name of the polyatomic ionthe cation followed by the name of the polyatomic ion.

SECTION

7.3 Names and Formulas for Ionic Compounds

Names for Ions and Ionic Compounds (Cont.)

SECTION

7.3 Section Check

Which subscripts would you most likely use for an ionic compound containing anuse for an ionic compound containing an alkali metal and a halogen? (Remember, 1 = no written subscript)1 no written subscript)A. 1 and 2

B. 2 and 1

C 2 and 3C. 2 and 3

D. 1 and 1

SECTION

7.3 Section Check

What is the name of the compound Ca(OH) ?Ca(OH)2?A. calcium oxide

B. calcium(I)oxide

C calcium hydroxideC. calcium hydroxide

D. calcium peroxide