# Do I have to name the ions individually when naming ionic compounds?

Aug 17, 2014

Yes. The positive ion (cation) is named first and the negative ion (anion) is named last. The first ion is always the cation, and its name is the same as the element from which it was derived. For example, the cation ($N {a}^{+}$) is derived from the element sodium (Na), and is named the sodium cation. There is one exception to naming cations, and that is the polyatomic cation ammonium ($N {H}_{\text{4}}^{+}$). Many of the transition metals form cations with different charges. For example, iron (Fe) can form cations with a 2+ and a 3+ charge. In that case, the name of the cation includes the charge as a Roman numeral. For example, the $F {e}^{\text{2+}}$ cation is called iron (II), and the $F {e}^{\text{3+}}$ is called iron(III).

The second ion is always the negatively charged ion (anion), and its name is the name of the element with the last one or two syllables removed and the suffix -ide added. For example, the anion formed from the element chlorine is named the chloride anion, and the anion formed from the element oxygen is named the oxide ion. There are also many polyatomic anions, such as the nitrate ion ($N {O}_{\text{3}}^{-}$) and the sulfate anion ($S {O}_{\text{4"^"2+}}$).

Examples
$N a C l$: sodium chloride (also commonly called table salt)
$C a C {l}_{2}$: calcium chloride
$N {a}_{\text{2}} O$: sodium oxide
$A g N {O}_{3}$: silver nitrate
$F e O$: iron(II) oxide
$F {e}_{2} {O}_{3}$: iron(III) oxide
$N {H}_{4} I$: ammonium iodide
$N {H}_{4} N {O}_{3}$: ammonium nitrate
$C u S {O}_{4}$: copper(II) sulfate (Cu can form 1+ and 2+ cations)