Naming Ionic Compounds - Ionic Names and Polyatomic Ions

Vocabulary flashcards covering ions, ionic naming rules, polyatomic ions, and example compounds.

Monatomic ion

An ion that consists of a single atom (e.g., Ca2+, Cl−).

Binary compound

A compound made from two different elements bonded together (in ionic form: a metal and a nonmetal).

Cation

A positively charged ion formed when a metal loses electrons; the cation’s name is the metal’s name.

Anion

A negatively charged ion formed when a nonmetal gains electrons; many end in -ide.

Ion

A charged particle produced by the loss or gain of electrons.

Polyatomic ion

An ion made of two or more atoms that together carry a charge (e.g., ammonium NH4+, nitrate NO3−).

Nomenclature of Ionic Compounds

Naming system: metal ion name + nonmetal ion name (nonmetal typically ends with -ide).

-ide suffix

Ending used for many nonmetal anions (e.g., chloride, oxide, sulfide).

Group 1 elements

+1 charge from losing 1 electron.

Group 2 elements

+2 charge from losing 2 electrons.

Group 17 elements

Gain 1 electron to form a -1 charge.

Group 18 elements

Noble gases that do not gain or lose electrons (charge 0).

Transition metal

Metals that can have multiple oxidation states; often named with Roman numerals.

Stock system

Using Roman numerals to denote the charge of transition metal ions (e.g., Fe2+ = Iron(II)).

Iron(II)

Fe2+; iron ion with a +2 charge.

Iron(III)

Fe3+; iron ion with a +3 charge.

Copper(I)

Cu+; copper ion with a +1 charge.

Copper(II)

Cu2+; copper ion with a +2 charge.

Gold(I)

Au+; gold ion with a +1 charge.

Gold(III)

Au3+; gold ion with a +3 charge.

Tin(II)

Sn2+; tin ion with a +2 charge.

Tin(IV)

Sn4+; tin ion with a +4 charge.

Lead(II)

Pb2+; lead ion with a +2 charge.

Lead(IV)

Pb4+; lead ion with a +4 charge.

Silver

Ag+; silver with a fixed +1 charge; no Roman numeral needed.

Zinc

Zn2+; zinc with a fixed +2 charge; no Roman numeral needed.

Oxide

O2−; oxide ion (oxygen with a -2 charge).

Chloride

Cl−; chloride ion (chlorine as -1 anion).

Nitrate

NO3−; polyatomic ion with -ate ending.

Nitrite

NO2−; polyatomic ion with -ite ending.

Chlorite

ClO2−; polyatomic ion with -ite ending (one fewer O than chlorate).

Chlorate

ClO3−; polyatomic ion with -ate ending (more O than chlorite).

Perchlorate

ClO4−; polyatomic ion with -ate ending and a per- prefix (most oxygen).

Hypochlorite

ClO−; polyatomic ion with -ite ending and hypo- prefix (fewest O).

Ammonium ion

NH4+; the only polyatomic cation.

Hydride

H−; hydride ion (hydrogen with a -1 charge).

Cyanide

CN−; polyatomic ion consisting of carbon and nitrogen.

Sulfide

S2−; sulfide ion.

Sulfate

SO4^2−; polyatomic ion with -ate ending.

Phosphide

P3−; polyatomic ion from phosphorus.

Calcium bromide

CaBr2; ionic compound formed from calcium ion and bromide ion.

Sodium fluoride

NaF; ionic compound formed from sodium ion and fluoride ion.

Magnesium oxide

MgO; ionic compound formed from magnesium ion and oxide ion.

Potassium iodide

KI; ionic compound formed from potassium ion and iodide ion.