c7 states of matter
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 c7 states of matter
- Apply c7 states of matter to exam-style questions
- Develop independent study skills
- Build cross-topic connections
Prerequisites
- Read the revision notes for c7 states of matter first (GCSE Revise summary)
- Key vocab to pre-teach: Solid, Liquid, Gas
- 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: c7 states of matter
Duration: 50 minutes
Starter Activity (5 minutes)
Quick Recall
Write down everything you already know about c7 states of matter. Then check against the key terms: Solid, Liquid, Gas. Use a mini-whiteboard or paper.
Main Content (35 minutes)
Parent/Teacher Guide:
Before lesson: Read the script below. Pre-teach key vocab: Solid, Liquid, Gas.
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: Solid, Liquid, Gas.
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: c7 states of matter. 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: c7 states of matter. 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 arrangement and movement of particles in a solid, a liquid and a gas.
Plenary (5 minutes)
Check Out
Your student states one thing they learned and one question they still have about c7 states of matter.
Lesson 2: Core Concepts: c7 states of matter
Duration: 50 minutes
Starter Activity (5 minutes)
Review Previous Lesson
Quick recap: write 3 key points from Lesson 1 on c7 states of matter. Check them against the notes below.
Main Content (35 minutes)
Solid: A state of matter where particles are arranged in a regular pattern and vibrate about fixed positions. There are strong forces of attraction between particles.
Liquid: A state of matter where particles can move past each other randomly but are still close together. There are moderate forces of attraction between particles.
Gas: A state of matter where particles move very fast in all directions and are far apart. There are very weak forces of attraction between particles.
Sublimation: A change of state directly from solid to gas (or gas to solid) without going through the liquid state.
Conservation of mass: When a substance changes state, the number and type of particles stays the same. The mass does not change. Only the arrangement and movement of particles changes.
Limitations: The simple particle model assumes particles are solid, inelastic spheres. It does not show the forces between particles. It does not show that particles are not all the same size. It does not show the gaps between particles.
| Term | Meaning | Example |
|---|---|---|
| Arrangement of particles | Regular, close together | Random, close together |
| Movement of particles | Vibrate about fixed positions | Move randomly around each other |
| Forces between particles | Strong (hold particles in place) | Moderate (keep particles close but allow movement) |
| Shape | Fixed shape | Takes shape of container |
| Volume | Fixed volume | Fixed volume |
| Compressibility | Cannot be compressed | Cannot be compressed |
| Density | High | Medium |
| (s) | Solid | Fe(s), NaCl(s) |
Practice (10 minutes)
Q: Foundation Describe the arrangement and movement of particles in a solid, a liquid and a gas.
Answer: Solid: Particles are arranged in a regular pattern, close together, and vibrate about fixed positions. Liquid: Particles are close together but can move randomly past each other. Gas: Particles are far apart and move very fast in all directions.
Plenary (5 minutes)
Explain Back
Your student teaches the key points back to you without looking. Fill any gaps immediately.
Lesson 3: Application: c7 states of matter
Duration: 50 minutes
Starter Activity (5 minutes)
Quick Recall
Recall the key terms: Solid, Liquid, Gas. 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 arrangement and movement of particles in a solid, a liquid and a gas.
Answer: Solid: Particles are arranged in a regular pattern, close together, and vibrate about fixed positions. Liquid: Particles are close together but can move randomly past each other. Gas: Particles are far apart and move very fast in all directions.
Q2: Foundation Bromine has a melting point of −7°C and a boiling point of 59°C. State the physical state of bromine at: (a) −20°C, (b) 25°C, (c) 80°C.
Answer: (a) −20°C is below the melting point (−7°C), so bromine is a solid. (b) 25°C is between the melting point (−7°C) and boiling point (59°C), so bromine is a liquid. (c) 80°C is above the boiling point (59°C), so bromine is a gas.
Q3: Foundation Name the changes of state that occur when: (a) ice becomes water, (b) water becomes steam, (c) steam becomes water, (d) water becomes ice.
Answer: (a) Melting. (b) Boiling / evaporation. (c) Condensing. (d) Freezing.
Q4: Higher Explain why the mass of a substance does not change when it changes state. Why is this a physical change rather than a chemical change?
Answer: The mass does not change because no particles are created or destroyed during a change of state - only the arrangement and movement of the particles changes. It is a physical change rather than a chemical change because no new substances are formed; the particles remain the same substance (e.g. H₂O remains H₂O whether solid, liquid or gas).
Q5: Higher State two limitations of the simple particle model and explain why each is a limitation.
Answer: Limitation 1: The model does not show the forces between particles. This is a limitation because intermolecular forces are crucial for explaining why substances have different melting points and states at different temperatures. Limitation 2: The model represents particles as solid spheres, but real atoms/molecules are not solid spheres. This is a limitation because real particles have internal structure (nucleus and electrons) and are mostly empty space.
Q6: Foundation Dry ice (solid CO₂) turns directly into gas at −78°C. What is this change of state called? Write an equation with state symbols.
Answer: This change of state is called sublimation (solid directly to gas). Equation: CO₂(s) → CO₂(g).
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: c7 states of matter
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 changes of state using the particle model. <div class="
When a solid is heated, particles gain energy and vibrate more vigorously. At the melting point, particles have enough energy to break free from their fixed positions and the regular arrangement collapses — the solid becomes a liquid. When a liquid is heated, particles move faster. At the boiling point, particles have enough energy to overcome the intermolecular forces holding them together and they escape entirely — the liquid becomes a gas where particles move rapidly in all directions and are far apart. During each state change, the temperature stays constant because the energy is being used to overcome forces between particles rather than increase kinetic energy. No particles are created or destroyed — mass is conserved. Mark scheme: 1 mark for particles gain energy; 1 mark for melting explanation (break fixed positions); 1 mark for boiling explanation (overcome intermolecular forces); 1 mark for constant temperature during state change; 1 mark for energy used to overcome forces; 1 mark for conservation of mass.
Exam Tips: When describing particle arrangement, always mention both arrangement AND movement for each state | For predicting state at a given temperature: below melting point = solid, between mp and bp = liquid, above boiling point = gas | Remember sublimation: solid → gas directly. Carbon dioxide and iodine are common examples | Changes of state are physical changes - no new substances are formed, and mass is conserved | For limitations of the particle model, focus on: no forces shown, particles are not really solid spheres, different sizes not shown | State symbols: (aq) means dissolved in water - do not confuse with (l)
Common Errors: Watch Out! Particles expand when heated. Wrong: particles expand when heated Correct: particles themselves do not expand; the gaps between particles increase as they move faster and further apart Boiling and evaporation are the same thing. Wrong: boiling = evaporation Correct: evaporation happens at any temperature from the surface only; boiling happens at a specific temperature throughout the liquid
AO3 - Reasoning & Interpretation: Analysis and Evaluation A student heats a pure substance and records the temperature every minute. The graph shows the temperature rising from 20°C to 80°C, then staying at 80°C for 3 minutes, then rising again to 150°C. Question: Sketch the heating curve. What is the melting point? Explain what is happening during the flat section. Answer: Melting point = 80°C. During the flat section, the substance is changing state from solid to liquid. The temperature stays constant because the energy being supplied is used to overcome the forces holding the particles in their fixed positions (intermolecular forces / lattice), rather than increasing the kinetic energy of the particles.
Stretch & Challenge (Grade 8-9):
- Synoptic links: explain how c7 states of matter connects to another Chemistry topic you have studied
- Real-world: research one real-world use or example of c7 states of matter
- Critical: "What are the limitations of the models used in c7 states of matter?"
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: Solid, Liquid, Gas (10 mins)
- Exam practice: One past-paper question on c7 states of matter from the board websites (15 mins)
- Extension: Explain c7 states of matter to someone else in your own words (10 mins)