Resources

Learning to Name and Write Formulas:

- Determining the type of compound you are working with.

- Applying the rules for naming or formula writing for that type of compound.

- Practicing until it becomes second nature.

How to Name Ions

You can tell that you have an ion when you see a postive (+) or negative (-) charge after the element or chemical compound. For example:

Mg²⁺,     F^-,     CO₃^2-,     Fe³⁺

For Single Element Ions (e.g. K⁺ , Mg²⁺,  P^3-)

• To name positive (+) ions write the name as from the Periodic Table and add the word 'ion' afterwards.
• To name negative (-) ions write the name from the Periodic Table but replace the ending with �ide�. Put the word 'ion' after the name.

For Single Element Ions of Transition Metals (e.g. Cu²⁺, Fe³⁺, Co³⁺

• Write the ionic charge (the +1, +2 ...) as a Roman Numeral and put parentheses around the charge. So Cu²⁺ would be the Copper (II)ion.
• While not transition metals, Pb, Sn should also have Roman Numerals with parentheses to show their charge..

For Polyatomic Ions (e.g. CO₃^2-,  SO₄^-,  NH₄⁺):

• Look them up in your Table of Ions or have them memorized.