Write the formula for the polyatomic ion in fe(hco3)3. express your answer as an ion.

Ions can be atomic or molecular. If an atom contains either positive or negative charge it said to be atomic cation or atomic anion.

When a molecule carry positive or negative charge it is called as polyatomic cation or polyatomic anion. Generally charged or ionized molecules are called as polyatomic ions.

In given question Fe(HCO₃)₃ ionizes as follow,

                         Fe(HCO₃)₃    →    Fe³⁺  +  3 HCO₃⁻

The Ions produced are Fe³⁺ and HCO₃⁻. Fe³⁺ is said to be atomic (Ferric) ion and HCO₃⁻ (Bicarbonate) is polyatomic ion or molecular ion.