CHM013 · Bonding & Molecular Shape · Classes 8–12
Ionic Bonding
Objective: To model how electron transfer forms ions and an ionic bond.
🧰 Virtual materials and apparatus
- Virtual shell models of a metal and a non-metal
- Moving electrons
📐 Formulas and SI units
metal → cation + e⁻; non-metal + e⁻ → anion
total positive charge = total negative charge
💡 Theory
A metal atom loses its few outer electrons to become a positive ion; a non-metal gains electrons to complete its outer shell and becomes a negative ion. The oppositely charged ions attract strongly: this is an ionic bond. The formula balances the charges, e.g. Mg²⁺ with two Cl⁻ gives MgCl₂.
🪜 Guided virtual procedure
- Choose Na + Cl.
- Watch the electron move from sodium to chlorine.
- Read the ions formed and the formula.
- Try Mg + Cl: count how many chlorine atoms are needed.
- Write the formulas of all four compounds.
📋 Observations Simulated values
✅ Result and conclusion
Sodium gives one electron to chlorine, forming Na⁺ and Cl⁻, which attract to make NaCl.
🔬 Real lab vs simulation
Real ionic compounds form giant lattices, not pairs; the energy also depends on the lattice. Sodium and chlorine are hazardous elements, so this reaction is only ever shown, not done.
⚠️ Safety
Sodium metal and chlorine gas are dangerous; this is a conceptual animation only.
❓ Quick check
1. A metal atom forming an ion…
2. Formula from Mg²⁺ and Cl⁻?
3. Ionic bonds are attractions between…
🏋️ Practice
EasyIons in MgO?
Answer: Mg²⁺ and O²⁻
MediumElectrons moved to form CaCl₂?
Answer: 2
ChallengeWhy do ionic compounds have high melting points?
Answer: Strong attractions in a giant lattice