Ionic Nomenclature & Formula Writing

What type of elements form ionic compounds?

A metal and a nonmetal.

What particles make up an ionic compound?

Cations and anions.

What holds an ionic compound together?

Electrostatic attraction between oppositely charged ions.

What is a cation?

A positively charged ion.

What is an anion?

A negatively charged ion.

Which ion is written first in an ionic formula?

The cation.

Which ion is named first in an ionic compound?

The cation.

How is the name of a monatomic anion changed?

End the element name with "-ide."

What is the general naming rule for ionic compounds?

Cation name + anion name.

What is the general formula-writing rule for ionic compounds?

Total positive charge must equal total negative charge.

What is the overall charge of every ionic compound?

Zero (electrically neutral).

What is the lowest whole-number ratio of ions called?

A formula unit.

Do ionic compounds exist as molecules?

No. They exist as formula units in a crystal lattice.

What is the formula for sodium chloride?

NaCl

Name NaCl

Sodium chloride

What is the formula for potassium bromide?

KBr

Name KBr

Potassium bromide

What is the formula for calcium oxide?

CaO

Name CaO

Calcium oxide

What is the formula for magnesium sulfide?

MgS

Name MgS

Magnesium sulfide

What is the formula for aluminum oxide?

Al₂O₃

Name Al₂O₃

Aluminum oxide

What is the formula for calcium chloride?

CaCl₂

Name CaCl₂

Calcium chloride

What is the formula for magnesium fluoride?

MgF₂

Name MgF₂

Magnesium fluoride

What is the formula for aluminum nitride?

AlN

Name AlN

Aluminum nitride

How do you determine subscripts in an ionic compound?

Balance the total positive and negative charges.

Should subscripts always be reduced?

Yes, to the lowest whole-number ratio.

Why is Na₂Cl incorrect?

Sodium is +1 and chlorine is −1, so NaCl is already neutral.

Why is MgO not Mg₂O₂?

The ratio must be reduced to the lowest whole numbers.

What is the charge of Group 1 metals?

+1

What is the charge of Group 2 metals?

+2

What is the charge of aluminum?

+3

What is the charge of silver?

+1

What is the charge of zinc?

+2

What is the charge of cadmium?

+2

What is the charge of fluoride?

−1

What is the charge of chloride?

−1

What is the charge of bromide?

−1

What is the charge of iodide?

−1

What is the charge of oxide?

−2

What is the charge of sulfide?

−2

What is the charge of nitride?

−3

What is the charge of phosphide?

−3

What is a fixed-charge metal?

A metal that forms only one common ion.

Do fixed-charge metals require Roman numerals?

No.

What is a variable-charge metal?

A metal that can form more than one cation.