Writing & NamingFormulas

of Ionic & Covalent

Compounds

BondingTypes

Ionic, Covalent, or Metallic

• Review

Ionic Compounds

Crystalline Lattice

Ionic Compounds

• Contains a metal and nonmetal

• The valence electrons from the metal are transferred to the nonmetal.

• Metal is listed first, followed by the nonmetal.

• Change the name of the nonmetal to ~ide. – Examples: sulfide, oxide, phosphide.

• Ionic Example: NaClSodium Chloride

Ionic Binary Compound Naming Practice

1.Al2S3

2.Ba3P2

3.BaO

4.CaBr2

5.CsI

1.Aluminum Sulfide

More Ionic Binary Compounds Naming

Practice1.Fr2Cl

2.FrF

3.Sr3N2

4.K2O

5.Mg3P2

1.Francium Chloride

The 5 steps for writing a binary ionic compound

formula1. Write the symbols of the two

elements2. Write the oxidation number of

each as superscripts.3. Drop the positive and negative

signs4. Crisscross the superscripts so

they become subscripts. 5. Reduce when possible

Formula for Aluminum Oxide

1. Write the symbols of the elements

Al O

Formula for Aluminum Oxide

2. Write the oxidation numbers for each element

Al O+3

-2

Formula for Aluminum Oxide

3. Drop the positive & negative sign.

Al O3 2

Formula for Aluminum Oxide

4. Crisscross the superscripts so they become subscripts

Al O3 2

Formula for Aluminum Oxide

5. Reduce subscripts when possible. (not possible here)

Al O32

Examples of Reduction

of SubscriptsSr2O2

Al3P3

Pb2O4

Ba3N2

SrO

Ionic Binary Compound Formula Practice

1.Potassium iodide

2.Lithium bromide

3.Magnesium oxide

4.Sodium nitride

5.Radium phosphide

1. KI

More Ionic Binary Compound Formula

Practice1. Gallium Fluoride

2. Strontium chloride

3. Cesium sulfide

4. Aluminum bromide

5. Barium Phosphide

1. GaF3

Polyatomic Ions

Polyatomic (many atoms) ions are covalent molecules with a charge. They behave as if they were one-atom ion.

Polyatomic Ions

NH4+1

C2H3O2-1

ClO3-1

NO3-1

OH-1

CO3-2

SO4-2

PO4-3

Note: Ammonium is the only polyatomic ion with a + charge.

Treat polyatomic ions as you would an ion – crisscross to determine the formula.

The only difference is that when you have more than one of a Specific polyatomic ion in a formula you must encase

it in parenthesis.

Use your reference sheets to determine the name of the following polyatomics.

Writing Names with Polyatomics

1. Ca3(PO4)2

2. NH4Br

3. NaNO3

4. K2SO4

5. Mg(ClO3)2

1. Calcium Phosphate

As in all ionic compounds you must reduce subscripts, but you cannot change the formula of the polyatomic ion. You can only reduce subscripts outside the parenthesis.

Writing Names with Polyatomics

1. LiOH1. Lithium Hydroxide

2. Potassium

Carbonate

3. Barium Acetate

4. Ammonium Sulfide

5. Strontium Sulfate

Rolling AtomsInstructions:• Obtain a yellow cube and a blue cube • Roll the dice and using the elements that appear

on the tope face, write it’s name, ion, along with the correct formula and name for the compound in the template provided

• Use the dice to write 30 different compound formulas and names. You must have 30 different compounds!! After you reach 15, you will need to come up and get a new set

• When finished, you need to turn in your template and get a molecular naming review half sheet

Metal Nonmetal Metal Ion NM Ion Cmpd. Name Cmpd. Formula

1.

Covalent Compounds

Water Molecule

Hydrogen

Atom

Hydrogen

Atom

Oxygen Atom

Covalent Compounds

• Contains 2 or more nonmetals• The valence electrons are shared

between the nonmetals. • Must use prefixes in the name.• Name tells you the formula. – Example: N2O4 – dinitrogen tetroxide

• You CANNOT reduce the formulas

Covalent Prefixes

Mono -1Di – 2Tri – 3

Tetra – 4Penta – 5

Hexa – 6Hepta – 7Octa – 8Non – 9

Deca -10

A prefix tells you the number of atoms of that element in the

compound.

Naming Covalent Compounds

1. N2O3

2. CH4

3. PO5

4. S2F4

5. P4O10

1. Dinitrogen trioxide

Writing Formulas for Covalent Compounds

1. CO1. Carbon Monoxide

2. Phosphorus

Pentachloride

3. Sulfur hexafluoride

4. Dinitrogen trioxide

5. Sulfur dioxide

Ionic & Covalent Structure

Ionic Compounds

form a

crystalline lattice

– repeating

pattern of ions.

Covalent

compounds form

individual

molecules that

are not connected

to each other.

Na+1 Ions Cl-1 Ions

Sodium Chloride

Water

Name These Compounds

1. PCl3

2. Sr3N2

3. KOH

4. NO2

5. MgCO3

1. Phosphorus

trichloride

Write formulas for these compounds

1. Calcium Chlorate

2. Sodium Bromide

3. Sulfur hexafluoride

4. Carbon tetrachloride

5. Potassium

Phosphate

1. Ca(ClO3)2

Review of Ionic Compounds

Include Metals & NonmetalsYou need oxidation numbersName the metalChange the Nonmetal to –ide….Unless it has a polyatomic and

you give it it’s name…

Summing up: Ionic

• Ionic bonding occurs between a metal and a nonmetal. Metals lose all their valence electrons and become cations. Nonmetals gain enough electrons to fill their valence level and become anions.

• Always crisscross oxidation numbers and reduce to determine the formulas of ionic compounds

• Do not use prefixes in the names.• Ions form a crystalline lattice.

Summing up: Covalent

• Covalent bonding occurs when two nonmetals share electrons to fill their valence energy level.

• Never use oxidation numbers to determine the formula. There aren’t any since the two atoms share electrons, they do not take on a charge.

• Always use prefixes in the names.• Atoms combine to form individual

molecules.

WarmUp

1. What is necessary to write ionic compounds?

2. Which elements are involve d in ionic compounds?

3. When writing names for covalent compounds what must be included?

4. Which elements are involved in covalent compounds?

Chemical Formulas Vocab

Ionic CompoundsValence ElectronsPolyatomic IonsCovalent CompoundsPrefixesCrystalline Lattice StructureMolecules

RememberCovalent Bonds –• Molecules• 2 or more nonmetals• prefixes Phosphorus Pentachloride PCl5• name it with prefixes CO Carbon MonoxideIonic Bonds-• crystalline lattice• metal & nonmetal• criss cross oxidation numbers: Al+3O-2

Al2O3

• name as you see it Aluminum Oxide