Ionic Bonding | GCSE Chemistry

Bonding

Lesson overview

This lesson introduces the core chemistry idea, the useful equipment and the calculation or data skills used on this page.

Focusionic bonding and ionic lattices

Time45-60 minutes

EquipmentPeriodic table, calculator and notebook.

Practical linkuse models to explain observable properties

Maths tagscharges, formulae and ratio of ions

What you will learn

Describe the key chemistry ideas behind ionic bonding and giant ionic structures.
Use precise GCSE command-word language in explanations.
Apply the idea to unfamiliar substances, data or practical contexts.
Check answers using units, state symbols, observations or balanced equations where relevant.

Core knowledge

Ionic bonding happens when electrons are transferred from metal atoms to non-metal atoms.
Metals lose electrons to form positive ions; non-metals gain electrons to form negative ions.
Oppositely charged ions attract strongly in all directions in a giant ionic lattice.
Ionic compounds have high melting points because many strong electrostatic attractions must be overcome.
Ionic compounds conduct when molten or dissolved because their ions can move.

Ionic bonding infographic

Illustrated GCSE Chemistry infographic showing electron transfer from sodium to chlorine, formation of Na+ and Cl- ions, an ionic lattice and property links. — Use this infographic to connect electron transfer, oppositely charged ions, giant ionic lattices and key properties such as high melting point and conductivity when molten or dissolved.Download visual

Ionic Bonding practice set

Use the worked examples and practice questions on this page as a complete study task: learn the cation and anion meanings, summarise the infographic in your own words, then answer the questions using the data, equations and observations given here. Check every answer for charges, formulae and ratio of ions.

Clear explanation

Ionic bonding and giant ionic structures is built around ionic bonding and ionic lattices. Start by learning what cation and anion mean, then connect them to the sequence in the infographic.

The key GCSE skill is to move from evidence to explanation: name the observation, data trend, particle model, structure or reaction, then explain why it supports the conclusion.

For calculation or data work, show charges, formulae and ratio of ions. For written explanations, include the specific chemistry reason rather than a memorised topic sentence.

Worked examples

Core example: sodium chloride

Sodium has 2,8,1 and loses one electron.

Chlorine has 2,8,7 and gains one electron.

The ions are Na+ and Cl-.

Answer: Sodium chloride is a giant ionic lattice of Na+ and Cl- ions.

Extension example: magnesium chloride formula

Magnesium forms Mg2+.

Chlorine forms Cl-.

Two chloride ions balance one magnesium ion.

Answer: The formula is MgCl2.

Quick checks

Choose an answer, then check your thinking.

1. Which particle is transferred in ionic bonding?

Proton Neutron Electron

2. Why does solid sodium chloride not conduct?

Ions cannot move No charged particles It contains molecules

Practice questions

Question 1

Describe how a magnesium ion forms.

Reveal answer and marking guidance

Answer: A magnesium atom loses two electrons to form Mg2+.

Marking: Credit loss of two electrons and Mg2+.

Question 2

Explain why ionic compounds have high melting points.

Reveal answer and marking guidance

Answer: They have many strong electrostatic attractions between oppositely charged ions, requiring lots of energy to overcome.

Marking: Credit strong attractions, opposite ions and energy.

Question 3

Predict the formula from Al3+ and O2-.

Reveal answer and marking guidance

Answer: Al2O3, because +6 balances -6.

Marking: Credit formula and charge balance.

Question 4

Why does molten potassium bromide conduct?

Reveal answer and marking guidance

Answer: It has mobile ions that carry charge.

Marking: Credit mobile ions and charge.

Practice ladder

FluencyRecall the key definition, symbol, structure, equation or observation.

ApplicationApply ionic bonding and giant ionic structures to unfamiliar substances, practicals or data.

Practical interpretationUse evidence, method quality, uncertainty or conclusion wording where asked to evaluate.

Maths skillUse units, ratios, graphs and significant figures accurately.

Answers and marking guidance

The exact practice answers are hidden under each question so you can try first. Marks come from using the correct chemistry model, choosing the right equation where needed, keeping units with values, and explaining changes with precise words such as particles, ions, bonds, energy, rate, evidence and uncertainty.

Common mistakes

Drawing ionic bonding as shared electrons.
Forgetting to balance charges in formulae.
Saying ionic solids conduct electricity.
Calling an ionic lattice a molecule.

Extension challenge

Create a six-line revision card for ionic bonding and giant ionic structures: two definitions, one infographic detail or equation line, one equation or data check, one common mistake, and one complete explanation sentence using cation, anion, lattice.

Reveal answer

Example answer: A complete response names the chemistry model, uses accurate units or observations, and explains why the evidence supports the conclusion.