c6 metallic bonding
4 detailed 50-minute lessons with teaching scripts, worked examples, parent guides, and assessment criteria.
Lesson Overview
Total Lessons: 4
Tier: Foundation and Higher
Duration: 50 minutes per lesson (200 minutes total)
Exam Boards: AQA, Edexcel, OCR, Eduqas, CCEA
Tier: Foundation and Higher
Duration: 50 minutes per lesson (200 minutes total)
Exam Boards: AQA, Edexcel, OCR, Eduqas, CCEA
Learning Objectives
- Explain the key ideas of c6 metallic bonding
- Apply c6 metallic bonding to exam-style questions
- Develop independent study skills
- Build cross-topic connections
Prerequisites
- Read the revision notes for c6 metallic bonding first (GCSE Revise summary)
- Key vocab to pre-teach: Metallic bonding, Delocalised electrons, Alloy
- Basic skills: reading the summary notes and answering the practice questions there
Materials & Equipment
- Exercise book, coloured pens
- Scientific calculator
- Ruler
- Printed revision notes (link below)
- Internet for videos (see Resources)
Lesson 1: Introduction: c6 metallic bonding
Duration: 50 minutes
Starter Activity (5 minutes)
Quick Recall
Write down everything you already know about c6 metallic bonding. Then check against the key terms: Metallic bonding, Delocalised electrons, Alloy. Use a mini-whiteboard or paper.
Main Content (35 minutes)
Parent/Teacher Guide:
Before lesson: Read the script below. Pre-teach key vocab: Metallic bonding, Delocalised electrons, Alloy.
If stuck: Re-read the revision notes (link above), then break the content into smaller steps.
Extension: See the Stretch & Challenge ideas in Lesson 4.
Before lesson: Read the script below. Pre-teach key vocab: Metallic bonding, Delocalised electrons, Alloy.
If stuck: Re-read the revision notes (link above), then break the content into smaller steps.
Extension: See the Stretch & Challenge ideas in Lesson 4.
Teaching Script (35 mins):
Mins 0-5 - Hook: "Today: c6 metallic bonding. By the end you will be able to answer exam questions on it unaided. It connects to the rest of Chemistry because the ideas here recur across the spec."
Mins 5-20 - Direct Instruction: Work through the core ideas below one at a time; after each, ask your student to explain it back in their own words.
Mins 20-30 - Guided Practice: Model the worked example together, then let your student attempt the first practice question with guidance.
Mins 30-35 - Independent Practice: 2-3 practice questions from Lesson 3 below, with immediate feedback.
Mins 0-5 - Hook: "Today: c6 metallic bonding. By the end you will be able to answer exam questions on it unaided. It connects to the rest of Chemistry because the ideas here recur across the spec."
Mins 5-20 - Direct Instruction: Work through the core ideas below one at a time; after each, ask your student to explain it back in their own words.
Mins 20-30 - Guided Practice: Model the worked example together, then let your student attempt the first practice question with guidance.
Mins 30-35 - Independent Practice: 2-3 practice questions from Lesson 3 below, with immediate feedback.
First Look
Start with the revision notes summary, then attempt: Foundation Describe the structure of a metal and explain what holds the structure together.
Plenary (5 minutes)
Check Out
Your student states one thing they learned and one question they still have about c6 metallic bonding.
Lesson 2: Core Concepts: c6 metallic bonding
Duration: 50 minutes
Starter Activity (5 minutes)
Review Previous Lesson
Quick recap: write 3 key points from Lesson 1 on c6 metallic bonding. Check them against the notes below.
Main Content (35 minutes)
Metallic bonding: The strong electrostatic attraction between positive metal ions and the sea of delocalised electrons. Metals form a giant lattice of positive ions surrounded by delocalised electrons.
Delocalised electrons: Electrons that have left their atoms and are free to move throughout the metallic structure. They come from the outer shell of metal atoms.
Alloy: A mixture of a metal with one or more other elements (usually another metal or carbon). Alloys are harder than pure metals because the different-sized atoms disrupt the regular arrangement of ions.
Shape memory alloy: An alloy that can return to its original shape after being deformed when it is heated. Example: Nitinol (nickel-titanium alloy) used in dental braces and stents.
Key principle: The strong electrostatic attraction between the positive metal ions and the negative delocalised electrons holds the structure together. This is metallic bonding. The more delocalised electrons per atom, the stronger the metallic bonding.
Why alloys are harder: In a pure metal, all the ions are the same size so the layers can slide easily. In an alloy, the different-sized atoms disrupt the layers, preventing them from sliding, making the alloy harder and stronger.
| Term | Meaning | Example |
|---|---|---|
| Good conductors of electricity | Delocalised electrons can move throughout the structure and carry charge | |
| Good conductors of thermal energy | Delocalised electrons transfer energy quickly through the structure | |
| Malleable (can be hammered into shape) | Layers of positive ions can slide over each other while still being held together by the sea of delocalised electrons | |
| Ductile (can be drawn into wires) | Same reason - layers can slide without breaking the metallic bonds | |
| High melting and boiling points | Strong electrostatic attraction between positive ions and delocalised electrons requires a lot of energy to overcome | |
| Shiny/lustrous | Delocalised electrons reflect light | |
| Structure | Regular layers of same-sized ions | Mixture of different-sized atoms disrupts layers |
| Hardness | Softer (layers slide easily) | Harder (layers cannot slide easily) |
Practice (10 minutes)
Q: Foundation Describe the structure of a metal and explain what holds the structure together.
Answer: A metal consists of a giant lattice of positive metal ions surrounded by a "sea" of delocalised electrons (electrons that have left the outer shell of the metal atoms). The strong electrostatic attraction between the positive ions and the negative delocalised electrons holds the structure together - this is metallic bonding.
Plenary (5 minutes)
Explain Back
Your student teaches the key points back to you without looking. Fill any gaps immediately.
Lesson 3: Application: c6 metallic bonding
Duration: 50 minutes
Starter Activity (5 minutes)
Quick Recall
Recall the key terms: Metallic bonding, Delocalised electrons, Alloy. Define each in one sentence.
Main Content (35 minutes)
Parent/Teacher Guide: Let your student attempt each question alone first, then compare with the model answer. Award method marks for correct working even if the final answer is wrong.
Q1: Foundation Describe the structure of a metal and explain what holds the structure together.
Answer: A metal consists of a giant lattice of positive metal ions surrounded by a "sea" of delocalised electrons (electrons that have left the outer shell of the metal atoms). The strong electrostatic attraction between the positive ions and the negative delocalised electrons holds the structure together - this is metallic bonding.
Q2: Foundation Explain why metals are good conductors of electricity and heat.
Answer: Metals conduct electricity because the delocalised electrons are free to move throughout the structure and can carry charge (current). Metals conduct heat because the delocalised electrons can transfer kinetic energy quickly through the structure when they gain energy from heating.
Q3: Foundation Explain why pure metals are malleable but ionic compounds are brittle.
Answer: Metals are malleable because the layers of positive ions can slide over each other while still being held together by the delocalised electrons - the metallic bonds are not broken. Ionic compounds are brittle because when a force causes the layers to shift, like-charged ions are brought next to each other. The strong repulsion between like charges causes the structure to shatter.
Q4: Higher Explain why an alloy is harder than a pure metal. Use a diagram description in your answer.
Answer: In a pure metal, all the atoms are the same size so they form a regular arrangement. When a force is applied, the layers of same-sized ions can slide over each other easily. In an alloy, atoms of different sizes are mixed into the structure. These different-sized atoms disrupt the regular arrangement of the metal ions, making it much harder for the layers to slide over each other. This makes the alloy harder than the pure metal.
Q5: Higher Magnesium has a higher melting point than sodium. Explain this difference using ideas about metallic bonding.
Answer: Magnesium atoms lose 2 electrons each to become Mg²⁺ ions, while sodium atoms lose only 1 electron each to become Na⁺ ions. This means there are twice as many delocalised electrons per ion in magnesium compared to sodium. The greater number of delocalised electrons and the higher charge on the Mg²⁺ ions mean there is stronger electrostatic attraction between the ions and electrons in magnesium. This stronger metallic bonding requires more energy to overcome, giving magnesium a higher melting point.
Plenary (5 minutes)
Error Review
Review any questions answered incorrectly. Identify whether the error was knowledge, method, or reading the question.
Lesson 4: Exam Practice: c6 metallic bonding
Duration: 50 minutes
Starter Activity (5 minutes)
Command Words
Review what these command words require: state (one point), describe (say what happens), explain (say why), compare (both sides), evaluate (judgement).
Main Content (35 minutes)
Extended Answer
Extended question: Extended Answer 6 marks: Explain why metals conduct electricity and why alloys are harder than pure metals. <div class="
Metals conduct electricity because the delocalised electrons in the metallic structure are free to move throughout the lattice. When a voltage is applied, these mobile electrons can carry charge through the metal, creating an electric current. Alloys are harder than pure metals because they contain atoms of different sizes mixed into the regular lattice. In a pure metal, all the ions are the same size so the layers can slide over each other easily. In an alloy, the different-sized atoms disrupt the regular arrangement, making it much harder for the layers to slide over each other. This makes the alloy harder and more resistant to deformation. Mark scheme: 1 mark for delocalised electrons free to move; 1 mark for carrying charge / current; 1 mark for pure metal layers slide easily (same-sized ions); 1 mark for alloy has different-sized atoms; 1 mark for these disrupt the layers; 1 mark for layers cannot slide easily = harder.
Exam Tips: When describing metallic bonding, always mention: positive ions, delocalised electrons, electrostatic attraction, and the sea of electrons | The phrase "sea of delocalised electrons" is a key phrase examiners look for | For explaining malleability: "layers of ions can slide" + "delocalised electrons move with them" + "metallic bonds are maintained" | For alloys, always mention "different-sized atoms disrupt the layers" - this is the key explanation | Comparing melting points of metals: more delocalised electrons = stronger metallic bonding = higher melting point | Common mistake: saying "metal atoms" are in the lattice - it is "positive metal ions" (the atoms have lost their outer electrons)
Common Errors: Watch Out! Alloys are always stronger than pure metals. Wrong: alloys are always stronger Correct: alloys are harder (layers cannot slide easily), but "stronger" depends on the property measured — they are more resistant to deformation Metals conduct because of free electrons. Wrong: metals conduct because of free electrons Correct: metals conduct because of delocalised electrons — the term "delocalised" is more precise because these electrons belong to the whole structure, not just one atom
AO3 - Reasoning & Interpretation: Analysis and Evaluation An engineer needs to select an alloy for a bridge cable that must be very strong and resistant to bending. Data for three alloys: Alloy Composition Hardness (relative) Corrosion resistance Mild steel Fe + 0.2% C Medium Low Stainless steel Fe + Cr + Ni High High Brass Cu + Zn Medium Medium Question: Which alloy is most suitable? Justify your choice using the data. Answer: Stainless steel — it has the highest hardness (different-sized Cr and Ni atoms disrupt the iron lattice most) and the highest corrosion resistance, which is important for a bridge exposed to weather.
Stretch & Challenge (Grade 8-9):
- Synoptic links: explain how c6 metallic bonding connects to another Chemistry topic you have studied
- Real-world: research one real-world use or example of c6 metallic bonding
- Critical: "What are the limitations of the models used in c6 metallic bonding?"
Plenary (5 minutes)
Assessment Criteria
- Got it: Confident explanation + correct worked examples
- Getting there: Main points OK, needs support with detail
- Not yet: Confused on key concepts - re-run Lesson 2
Homework & Consolidation
- Consolidation: Re-answer any Lesson 3 practice questions answered incorrectly (20 mins)
- Retrieval: Write flashcards for the key terms: Metallic bonding, Delocalised electrons, Alloy (10 mins)
- Exam practice: One past-paper question on c6 metallic bonding from the board websites (15 mins)
- Extension: Explain c6 metallic bonding to someone else in your own words (10 mins)