Ion Reference Sheet: Monatomic and Polyatomic Ions

Comprehensive vocabulary flashcards covering monatomic and polyatomic ion nomenclature, charges, formulas, and classification rules.

Ion

An atom or group of atoms that has a positive or negative charge due to the loss or gain of electrons.

Monatomic Ion

An ion formed from a single atom, such as the sodium ion ($Na^+$).

Polyatomic Ion

An ion formed from a group of bonded atoms (more than one atom), such as the nitrate ion ($NO_3^-$).

Cation

A positive ion formed when metallic elements lose electron(s).

Anion

A negative ion formed when non-metallic elements gain electron(s), with the element name ending changed to "-ide".

Monovalent Ion

A monatomic ion having only one possible charge.

Multivalent Metallic Ion

A monatomic metallic ion having more than one possible charge, where Roman numerals indicate the charge in the written chemical name.

Hydride Ion

A non-metallic anion formed by hydrogen when it gains an electron, resulting in a 1- charge ($H^-$).

Zinc Ion

A monovalent metallic ion with a constant charge of 2+ ($Zn^{2+}$).

Cadmium Ion

A monovalent metallic ion with a constant charge of 2+ ($Cd^{2+}$).

Silver Ion

A monovalent metallic ion with a constant charge of 1+ ($Ag^+$).

Mercury(I) Ion

A polyatomic ion with an overall charge of 2+ composed of two bonded mercury atoms, written as $Hg_2^{2+}$.

Mercury(II) Ion

A monatomic multivalent ion of mercury with a charge of 2+, written as $Hg^{2+}$.

Ammonium Ion

A polyatomic cation with a 1+ charge and formula $NH_4^+$.

Acetate Ion

A polyatomic anion with a 1- charge and formula $C_2H_3O_2^-$ (or $CH_3COO^-$).

Hydrogen Carbonate (Bicarbonate) Ion

A polyatomic anion with a 1- charge and formula $HCO_3^-$.

Cyanide Ion

A polyatomic anion with a 1- charge and formula $CN^-$.

Hydroxide Ion

A polyatomic anion with a 1- charge and formula $OH^-$.

Nitrite Ion

A polyatomic anion with a 1- charge and formula $NO_2^-$.

Nitrate Ion

A polyatomic anion with a 1- charge and formula $NO_3^-$.

Carbonate Ion

A polyatomic anion with a 2- charge and formula $CO_3^{2-}$.

Sulfite Ion

A polyatomic anion with a 2- charge and formula $SO_3^{2-}$.

Sulfate Ion

A polyatomic anion with a 2- charge and formula $SO_4^{2-}$.

Phosphite Ion

A polyatomic anion with a 3- charge and formula $PO_3^{3-}$.

Phosphate Ion

A polyatomic anion with a 3- charge and formula $PO_4^{3-}$.

Hypochlorite Ion

A polyatomic anion with a 1- charge and formula $ClO^-$, containing chlorine and oxygen.

Chlorite Ion

A polyatomic anion with a 1- charge and formula $ClO_2^-$.

Chlorate Ion

A polyatomic anion with a 1- charge and formula $ClO_3^-$.

Perchlorate Ion

A polyatomic anion with a 1- charge and formula $ClO_4^-$.

Permanganate Ion

A polyatomic anion with a 1- charge and formula $MnO_4^-$.

Thiocyanate Ion

A polyatomic anion with a 1- charge and formula $SCN^-$.

Oxalate Ion

A polyatomic anion with a 2- charge and formula $C_2O_4^{2-}$.

Chromate Ion

A polyatomic anion with a 2- charge and formula $CrO_4^{2-}$.

Dichromate Ion

A polyatomic anion with a 2- charge and formula $Cr_2O_7^{2-}$.

Peroxide Ion

A polyatomic anion with a 2- charge and formula $O_2^{2-}$.

Thiosulfate Ion

A polyatomic anion with a 2- charge and formula $S_2O_3^{2-}$.