You will learn
- State the law of reflection.
- Draw ray diagrams.
- Describe a mirror image.
- Compare regular and diffuse reflection.
Version 0.2 · expanded edition · built from cited public sources Content is based on the official frameworks and sources listed under Sources and standards. No official endorsement is claimed. Written in the style of common primary school assessments. No exam result is promised.
Student lesson
- Angle of incidence equals angle of reflection.
- Angles are measured from the normal.
- A plane mirror image is the same size and reversed left to right.
- Rough surfaces scatter light.
Words to know
light bouncing off a surface
a line at right angles to the surface
the ray that hits the mirror
the ray that bounces off
1. Discover: The bathroom mirror
Esi steps back from the mirror and sees her reflection step back too. “The image appears as far behind the mirror as you are in front,” says Mr Kudjo. “And your left hand looks like the image’s right.”
Think: Why can you see a paper but not a clear image in it?
2. Understand: Reflection
Idea 1: The law
Reflection is light bouncing off a surface. The angle of the incident ray equals the angle of the reflected ray, both measured from the normal.
Idea 2: Images
A plane mirror makes an upright image the same size as you, the same distance behind the mirror, reversed left to right.
Idea 3: Surfaces
A smooth surface gives regular reflection and a clear image. A rough surface scatters light in many directions (diffuse reflection) so no clear image forms, but we can still see the object.
3. Worked examples
Example 1 (I show you): Draw
Ray.
- Normal.
- Incident.
- Reflected.
Answer: Equal angles.
Example 2 (We do it together): Describe
Image.
- Same size.
- Behind mirror.
- Reversed.
Answer: Plane image.
Example 3 (You try): Compare
Surfaces.
Show the steps and answer
- Smooth.
- Rough.
- Scatter.
Answer: Regular vs diffuse.
Did you know?
The mirrors on the James Webb Space Telescope are coated with a thin layer of gold, which reflects infrared light very well.
Why this matters
Reflection lets us use mirrors, periscopes, reflectors and telescopes.
4. Explore: Ray box with mirror
Shine a torch through a slit onto a plane mirror laid on paper, trace the incident and reflected rays, draw the normal and measure the angles.
- Place the mirror.
- Shine a thin beam.
- Mark the rays.
- Measure the angles.
Think about it: what did you notice?
What did you notice? The angles were equal.
5. Practise
Say it in a sentence
Use these starters when you talk about the lesson. Say them out loud.
- ___ is light bouncing off a surface.
- The ___ is a line at right angles to the surface.
- The ___ ray hits the mirror.
- The ___ ray bounces off.
Guided practice
Question 1. What is reflection?
Bouncing.
Question 2. What is the normal?
Right-angle line.
Question 3. Law?
Equal angles.
Independent practice
Level 1: Start
- What is reflection?
- What is the normal?
- Law?
- Where is the image?
- What reverses?
Level 2: Grow
- Why equal?
- Why rough scatters?
- Why see paper?
Level 3: Stretch
- Trace rays.
- Measure.
- Explain.
Answers are in the answer key below. Try first, then check.
6. Apply: Science in everyday life
Explain the law of reflection.
Show a sample answer
Use a diagram.
Another one. Tell a family member one thing from this lesson. Use the words you learned.
Show a sample answer
A clear sentence that uses at least one word from Words to know.
7. Common mistakes
Fix: Appears behind.
Fix: Diffuse reflection.
8. Lesson summary and revision card
- I can state the law of reflection.
- I can draw ray diagrams.
- I can describe a mirror image.
- I can compare regular and diffuse reflection.
9. Check and master
Answer all 14 questions. You will see feedback after each one.
Your result appears here after you answer every question.
10. Key takeaways
- Angle of incidence equals angle of reflection.
- Angles are measured from the normal.
- A plane mirror image is the same size and reversed left to right.
- Rough surfaces scatter light.
11. Next lesson
Next lesson: Refraction introduction. Keep going with the next idea in this course.
Exam practice
These questions are written in the style of common school and international primary assessments. Try them on your own, without looking back. Then check your answers in the marking guide. The marks are shown in brackets.
- Define reflection and normal. [2 marks]
- Draw a ray diagram showing the law. [3 marks]
- Compare regular and diffuse reflection. [3 marks]
- Safety rule. [2 marks]
Total: 10 marks.
Marking guide and model answers
- 1 each
- Normal [1]; two rays [1]; equal angles [1]
- Smooth [1]; rough [1]; image difference [1]
- Any [1]; reason [1]
Score guide: 9 to 10 = secure. 6 to 8 = nearly there, revise the parts you missed. Under 6 = work through the lesson again with a grown-up.
Printable worksheet
- What is reflection?
- What is the normal?
- Law?
- Where is the image?
- What reverses?
- Why equal?
- Why rough scatters?
- Why see paper?
- Trace rays.
- Measure.
Homework
Test which household surfaces give a clear reflection.
Answer key and marking scheme
| Question | Expected response | Marks |
|---|---|---|
| 1. What is reflection? | Bouncing. | 1 |
| 2. What is the normal? | Right-angle line. | 1 |
| 3. Law? | Equal angles. | 1 |
| 4. Where is the image? | Behind mirror. | 1 |
| 5. What reverses? | Left and right. | 1 |
| 6. Why equal? | Law. | 1 |
| 7. Why rough scatters? | Uneven. | 1 |
| 8. Why see paper? | Diffuse light. | 1 |
| 9. Trace rays. | Diagram. | 1 |
| 10. Measure. | Table. | 1 |
| Total | 10 |
Independent practice answers. Level 1: 1 Bouncing.; 2 Right-angle line.; 3 Equal angles.; 4 Behind mirror.; 5 Left and right.. Level 2: 1 Law.; 2 Uneven.; 3 Diffuse light.. Level 3: 1 Diagram.; 2 Table.; 3 Sentence..
Quiz answers: 1 B, 2 C, 3 A, 4 B, 5 C, 6 A, 7 B, 8 C, 9 A, 10 B, 11 C, 12 A, Challenge 1 B, Challenge 2 C.
Mastery and remediation
| Objective | Bronze (Developing) | Silver (Proficient) | Gold (Advanced) |
|---|---|---|---|
| O1 State the law of reflection | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O2 Draw ray diagrams | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O3 Describe a mirror image | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O4 Compare regular and diffuse reflection | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
Courseversity badge thresholds (overall quiz score): Gold = 90–100%; Silver = 80–89.9%; Bronze = 70–79.9%. A badge is never a full record of progress.
If a learner struggles
- Find the misconception: “The image is inside the mirror.” Appears behind.
- Explain another way: use real objects, pictures or actions first, then words.
- Show a simpler example: State the law of reflection.
- Guided practice: work through one example together and let the learner try the next one.
- Reassess: use the quiz again or the worksheet.
- Move on when the learner shows Silver-level evidence independently.
For parents and guardians
In this lesson your child investigates reflection with safe light sources. You do not need to be an expert to help.
- Look in a mirror together.
- Ask “Where is the image?”
- Never use lasers.
- Ask “how do you know?” after each answer, and listen.
- Praise effort, not only right answers. Mistakes are how we learn.
- Ten to fifteen minutes a day is better than one long session.
Teacher package
1–5. Objectives, prerequisites, materials, preparation, duration
Lesson objectives. Learners will: state the law of reflection; draw ray diagrams; describe a mirror image; compare regular and diffuse reflection.
Prerequisite knowledge. Grade 5 ideas: energy forms, light, shadows, sound and heat.
Materials. Plane mirrors, torches, slits, protractors. Low-resource options: use chalk or charcoal on a board or wall, drawings in the sand, and objects from the classroom instead of printed materials.
Preparation. Check mirrors.
Suggested duration. 45–60 minutes. It can be split into two shorter sessions.
6–9. Teaching procedure, explanation notes, guided and independent activities
Introduction (5 min). Hold up a mirror and ask, “Why can I see myself?”
Explanation (10 min). Teach reflection.
Guided activity (10 min). Learners trace rays.
Independent activity (10 min). Learners explain.
Assessment and reflection (5 min). Ask each learner to say one thing they learned and how they know it.
Key questions. What are the angles? Is the surface smooth?
Teacher explanation notes. Start with real objects and safe, hands-on observation. Then talk about what was seen, then draw and write. Always say “how do you know?”. Keep to the safety notes, and use local, safe materials.
10–12. Differentiation, formative assessment, common misconceptions
Support. Use real objects and pictures, short sentences and a partner. Let learners point, show or draw instead of writing. Extension. Ask learners to find a new example at home and explain how they know.
Formative assessment. Listen to learners read and explain, ask “how do you know?”, and check the independent work.
Misconceptions. “The image is inside the mirror.” Appears behind.
13–15. Assessment questions, answer keys, marking scheme
Use the quiz, the 10-mark exam practice and the worksheet on this page. All answers and marking guides are in the answer sections above. Re-check every answer before use.
16–19. Remediation, enrichment, homework, teacher reflection
Remediation. State the law of reflection. Enrichment. Look for one new example near your home or school, draw it and explain it to someone. Homework. See above.
Teacher reflection. After teaching, record: which ideas learners understood; which misconceptions occurred; which activities worked; which learners need more practice; and what to improve next time.
Sources and standards
This lesson is based on the sources below, and no official endorsement is claimed. Reference starting points: Next Generation Science Standards, Cambridge Primary Science and the IB Primary Years Programme. Where a standard code is named, it points to the official framework.
Research used to shape this lesson. Courseversity Science curriculum, Grade 6 Unit 8, topic 6; Next Generation Science Standards, energy and waves; Cambridge Lower Secondary Science, physics; IB Primary Years Programme, how the world works. These sources informed the lesson.