Common Ions, Charges, and Naming Patterns

Vocabulary flashcards covering all common ions that must be memorized for AP Chemistry along with key naming rules and periodic trends for predicting ionic charges.

Silver ion

Ag⁺

Zinc ion

Zn²⁺

Mercury(I) ion

Hg₂²⁺

Ammonium ion

NH₄⁺

Cyanide ion

CN⁻

Hydroxide ion

OH⁻

Nitrite ion

NO₂⁻

Nitrate ion

NO₃⁻

Sulfite ion

SO₃²⁻

Sulfate ion

SO₄²⁻

Hydrogen sulfate (bisulfate) ion

HSO₄⁻

Phosphate ion

PO₄³⁻

Hydrogen phosphate ion

HPO₄²⁻

Dihydrogen phosphate ion

H₂PO₄⁻

Thiocyanate ion

NCS⁻

Carbonate ion

CO₃²⁻

Hydrogen carbonate (bicarbonate) ion

HCO₃⁻

Hypochlorite ion

ClO⁻

Chlorite ion

ClO₂⁻

Chlorate ion

ClO₃⁻

Perchlorate ion

ClO₄⁻

Hypobromite ion

BrO⁻

Bromite ion

BrO₂⁻

Bromate ion

BrO₃⁻

Perbromate ion

BrO₄⁻

Hypoiodite ion

IO⁻

Iodite ion

IO₂⁻

Iodate ion

IO₃⁻

Periodate ion

IO₄⁻

Acetate ion

C₂H₃O₂⁻

Permanganate ion

MnO₄⁻

Dichromate ion

Cr₂O₇²⁻

Chromate ion

CrO₄²⁻

Peroxide ion

O₂²⁻

Oxalate ion

C₂O₄²⁻

Amide ion

NH₂⁻

Borate ion

BO₃³⁻

Thiosulfate ion

S₂O₃²⁻

Iron(III) ion

Fe³⁺

Iron(II) ion

Fe²⁺

Copper(II) ion

Cu²⁺

Copper(I) ion

Cu⁺

Cobalt(III) ion

Co³⁺

Cobalt(II) ion

Co²⁺

Tin(IV) ion

Sn⁴⁺

Tin(II) ion

Sn²⁺

Lead(IV) ion

Pb⁴⁺

Lead(II) ion

Pb²⁺

Mercury(II) ion

Hg²⁺

Group 1 (alkali metal) ions

Always form +1 cations by losing one electron

Group 2 (alkaline earth metal) ions

Always form +2 cations by losing two electrons

Group 13 metal ions

Typically form +3 cations by losing three electrons

Group 17 (halogen) ions

Form −1 anions by gaining one electron; names end in –ide

Group 16 nonmetal ions

Form −2 anions by gaining two electrons

Group 15 nonmetal ions

Form −3 anions by gaining three electrons

“-ide” suffix

Indicates a monatomic anion (or some simple polyatomic ones)

Roman numerals in cation names

Show the charge of metals that can form multiple cations

“-ate” vs “-ite”

Polyatomic anions with the same central atom; “-ate” has one more O than “-ite” and same charge

Hydrogen addition to polyatomic ions

Adding H⁺ to an anion lowers its negative charge by 1 and prefixes the name with hydrogen or dihydrogen

“hypo-” prefix

Means one fewer oxygen than the “-ite” ion with the same charge

“per-” prefix

Means one more oxygen than the “-ate” ion with the same charge