IONIC COMPOUNDSNotes #12

Review To find the number of valence electrons in

an atom of a representative element, simply look at its group number.

Why do atoms form ions?

To fulfill octet rule.

To be stable and happy like a noble gas.

They gain and lose electrons to have a COMPLETE outer shell.

But where do these electrons come from?

OTHER ELEMENTS!

This creates something we call:

Ionic Compounds: Compounds that are formed by

elements transferring their electrons to each other.

Ionic Bonds: The electrostatic forces that hold ions

together in ionic compounds.

Ionic Compounds: Properties Are electrically neutral (no charge!)

Most ionic compounds are crystalline solids at room temperature.

Ionic Compounds: Properties Ionic compounds generally have high

melting points. Ionic compounds can conduct an

electric current when melted or dissolved in water.

How Ionic Compounds are made:

Naming. Easy Peasy.

Write the actual name of the cation. Then, write the name of the anion

with the end ending in –ide. Ex: Nitrogen Nitride; Oxygen Oxide;

etc

Cations always first, Anions always last

Practice

Cation always First.Anion Always Last.

Must be neutral… Criss-Cross Rule

Polyatomic Ions

Find these on your handout:

Ionic Compounds with polyatomic ions: Write the chemical formula and

name it:

Magnesium and nitrate

Lithium and sulfate

Potassium and cyanide

Transition Metals (Groups 1B to 8B) They always form CATIONS.

Therefore, they will have a positive charge.

The charges of the cations of many transition metal ions must be determined from the number of electrons lost.

Transition metals can form more than one ion. (Exceptions: Ag+, Cd+2, and Zn+2)

Symbols and Names of Common Transition Metal Ions

Symbol Stock Name Classical Name

Cu+ Copper (I) ion Cuprous ion

Cu+2 Copper (II) ion Cupric ion

Fe+2 Iron (II) ion Ferrous ion

Fe+3 Iron (III) ion Ferric ion

Co+2 Cobalt (II) ion Cobaltous ion

Co+3 Cobalt (III) ion Cobaltic ion

Practice

Cobalt (III) fluoride Copper (II) chloride

Fe2O3

CuF

Lab Activity

Cut and Paste Ionic Compounds!