Ionic Compounds
Related Examples and Practice Problems
Additional Worked Out Examples/ Practice
Identifying classification types: Differentiation between elements, compounds or mixtures and homogeneous and heterogenous mixtures
Separation techniques: Selected and explaining limitation of appropriate separation
Relating Properties to Composition: Predicting classification based on descriptive properties
Topic Summary & Highlights
and Help Videos
Core Concept
Ionic compounds are composed of a cation and anion. The cation is typically a metal, and the anion is usually a nonmetal or a polyatomic ion (a group of atoms with an overall charge). If the compound contains a metal it is a good sign that it can be considered an ionic compound.
Practice Tips
Memorize Common Ions: Focus on learning the common polyatomic ions, charges, and patterns.
Roman Numerals for Transition Metals: Practice associating transition metals with their possible charges.
Cross-Method for Formulas: To determine the correct formula, use the “criss-cross” method to balance charges between cations and anions.
Types of Ionic Compounds
Type I: Ionic compounds where the metal forms only one type of cation.
Type II: Ionic compounds where the metal can form multiple types of cations (transition metals with variable charges).
Type III: Compounds containing polyatomic ions.
WRITING FORMULA of Ionic Compounds
Write the symbols and charges for each cation and anion. (Cation is written first.)
Crisscross ONLY THE NUMBER (not +/-) OF THE CHARGE to the other ion - written as a subscript. (You may need to use parentheses if the cation or anion contains more than 1 element or has a subscript already written.)
Simplify the numbers that were crisscrossed (now written as subscripts). (If the subscript is reduced to “1” then it should not be written and parentheses are not needed.)
Writing Names for Ionic Compounds
