Students cut out cards showing cations, anions, and compound formulas, then match them correctly. This reinforces naming rules and helps students practice writing and recognizing ionic compounds.

1. Prepare three sets of cards: one with cation names, one with anion names, and one with chemical formulas.
2. Distribute sets of cards to student groups.
3. Students work to correctly match cations with anions to form the correct formulas.
4. Check answers and discuss naming rules for ionic compounds.

Card Examples (to cut and match)

Cations:

• Sodium (Na⁺)
• Calcium (Ca²⁺)
• Aluminum (Al³⁺)
• Potassium (K⁺)

Anions:

• Chloride (Cl⁻)
• Sulfide (S²⁻)
• Oxide (O²⁻)
• Nitrate (NO₃⁻)

Formulas:

• NaCl
• CaS
• Al₂O₃
• KNO₃

Putting Ions in their Hands - FlinnScientific:

• Add transition metals with variable charges (e.g., Fe²⁺, Fe³⁺) for advanced practice.
• Include polyatomic ions like sulfate (SO₄²⁻), carbonate (CO₃²⁻), or phosphate (PO₄³⁻).
• Turn it into a timed race between student groups.

• None required for paper-based activity.

• How do you determine the correct ratio of ions in a compound? (By balancing charges so the total positive and negative charges equal zero.)
• Why do ionic compounds form crystal lattices instead of discrete molecules? (Because the electrostatic attraction extends in all directions.)
• How do polyatomic ions change the naming and formula rules? (They act as a single charged unit, often requiring parentheses in formulas.)