Naming Ions and Ionic Compounds – Lesson Summary

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Learning Objective

In this lesson we will learn how ions and ionic compounds are named.

Learning Outcomes

By the end of this lesson you will be able to:

  • Name positive and negative monatomic ions.
  • Give examples of metals that form more than one type of ion, and show how these ions are differentiated.
  • Look up the names and formulas of polyatomic ions on a valency table.
  • Determine the names of ionic compounds from their formulas.

 
naming ions and ionic compounds lesson contents

(Image: antoine2k, Adobe Stock)

Lesson Topics

1 | Names for Monatomic Ions

2 | Names for Polyatomic Ions

3 | Names for Ionic Compounds

4 | Summary

Lesson Summary

  • Monatomic ions are ions that contain one type of atom.
  • Polyatomic ions are ions that contain more than one type of atom.
  • Monatomic positive ions have the same name as the metal atoms they are formed from.
  • For metals that form more than one type of ion, Roman numerals corresponding to the size of the positive charge are used to distinguish between the different ions.
  • Monatomic negative ions have the same name as the non-metal atoms they are formed from, except the last part of their name is changed to “-ide”.
  • The names of polyatomic ions cannot be predicted from their formulas, but can be looked up in a valency table.
  • The names of ionic compounds are derived by joining the names of the positive and negative ions they are composed of.
  • The positive ion forms the first part of the compound name.
  • The negative ion forms the second part of the compound name.

 
sodium chloride ions lattice

Sodium chloride lattice, showing sodium and chloride ions.