4CH1
Ionic Bonding
Principles of Chemistry · 2 question types
Exam Frequency Analysis
Past paper frequency (2018 to 2024)
This topic accounts for approximately 9% of your exam marks.
stable
Medium
Stable9%
Ion formation, lattice structures and properties of ionic compounds tested consistently.
The charges of a fixed set of common ions must be learnt by heart.
Positive ions (cations)
| Ion | Charge | Example |
|---|---|---|
| Group 1 metal | 1+ | Li⁺, Na⁺, K⁺ |
| Group 2 metal | 2+ | Mg²⁺, Ca²⁺ |
| Group 3 metal | 3+ | Al³⁺ |
| Silver | 1+ | Ag⁺ |
| Copper(II) | 2+ | Cu²⁺ |
| Iron(II) | 2+ | Fe²⁺ |
| Iron(III) | 3+ | Fe³⁺ |
| Lead(II) | 2+ | Pb²⁺ |
| Zinc | 2+ | Zn²⁺ |
| Hydrogen | 1+ | H⁺ |
| Ammonium | 1+ | NH₄⁺ |
Negative ions (anions)
| Ion | Charge | Example |
|---|---|---|
| Group 5 non-metal | 3− | N³⁻ |
| Group 6 non-metal | 2− | O²⁻, S²⁻ |
| Group 7 non-metal | 1− | F⁻, Cl⁻, Br⁻, I⁻ |
| Hydroxide | 1− | OH⁻ |
| Nitrate | 1− | NO₃⁻ |
| Carbonate | 2− | CO₃²⁻ |
| Sulfate | 2− | SO₄²⁻ |
- Polyatomic (NH₄⁺, OH⁻, NO₃⁻, CO₃²⁻, SO₄²⁻) are clusters of atoms that carry their charge as a single unit. Treat them as one piece in any formula you build
Exam tip
Defining ionic bonding
What comes up: "State what is meant by the term ionic bonding." (2 marks)
Write (two marks): (1) Electrostatic attraction (2) between oppositely charged ions.
Watch out: The mark scheme rejects any response that implies covalent bonding for M2. You do not need to mention electron transfer here — the definition is purely about the nature of the force that holds the ions together, not how the ions were created.