Reflection of Light

Active learning lets students test the law of reflection directly. When they move mirrors and light sources, they see the equal angles in real time. This tactile experience builds intuition that static diagrams alone cannot match.

• 5th Class
• Scientific Inquiry and the Natural World
• 4 activities
• 30 min–50 min

Learning Objectives

1. Explain the law of reflection, stating the relationship between the angle of incidence and the angle of reflection.
2. Compare the image characteristics (size, orientation, location) formed by plane, concave, and convex mirrors.
3. Analyze ray diagrams to predict the location and nature of images formed by concave mirrors.
4. Design an experiment to demonstrate multiple reflections using two or more mirrors.
5. Identify applications of reflection in everyday objects and technologies.

Stations Rotation

⏱ 45 min·Small Groups

Stations Rotation: Mirror Image Stations

Prepare stations with plane, concave, and convex mirrors plus objects like candles. Students place objects at varying distances, observe and sketch images, then draw ray diagrams. Groups rotate every 10 minutes and discuss image properties.

Prepare & details

Explain the law of reflection and its application to mirrors.

Facilitation Tip: During Mirror Image Stations, circulate with a timer and remind groups to rotate every 4 minutes so no station is crowded.

Setup: Tables/desks arranged in 4-6 distinct stations around room

Materials: Station instruction cards, Different materials per station, Rotation timer

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Inquiry Circle

⏱ 30 min·Pairs

Pairs Experiment: Angle Measurement

Provide each pair with a flat mirror, protractor, ray box or laser, and paper. Shine light at different angles, measure incidence and reflection angles, record data in a table. Pairs verify the law holds across trials.

Prepare & details

Analyze how different types of mirrors form images.

Facilitation Tip: For Angle Measurement, provide colored pencils so students can trace rays and angles on protractor diagrams right away.

Setup: Groups at tables with access to source materials

Materials: Source material collection, Inquiry cycle worksheet, Question generation protocol, Findings presentation template

• Analyze
• Evaluate
• Create
• Self-Management
• Self-Awareness

Inquiry Circle

⏱ 50 min·Small Groups

Small Groups: Periscope Build

Supply cardboard tubes, mirrors cut at 45 degrees, tape, and cutters. Groups assemble periscopes, test viewing around obstacles, adjust angles for clear images. Share designs and improvements with the class.

Prepare & details

Design an experiment to demonstrate multiple reflections.

Facilitation Tip: When building periscopes, distribute pre-cut cardstock tubes and mirrors to ensure quick assembly and focus on alignment.

Setup: Groups at tables with access to source materials

Materials: Source material collection, Inquiry cycle worksheet, Question generation protocol, Findings presentation template

• Analyze
• Evaluate
• Create
• Self-Management
• Self-Awareness

Inquiry Circle

⏱ 35 min·Whole Class

Whole Class: Multiple Reflections Demo

Use two mirrors at adjustable angles to create infinite images of a light source. Students predict image count based on angle, measure with protractors, observe changes as angles vary. Class discusses patterns.

Prepare & details

Explain the law of reflection and its application to mirrors.

Facilitation Tip: After the Multiple Reflections Demo, pause to ask each group: 'What happened to the light’s path when it hit two mirrors?' to prompt observation.

Setup: Groups at tables with access to source materials

Materials: Source material collection, Inquiry cycle worksheet, Question generation protocol, Findings presentation template

• Analyze
• Evaluate
• Create
• Self-Management
• Self-Awareness

Teaching This Topic

Start with plane mirrors so students grasp the basic law before adding curve complexity. Avoid rushing to concave and convex mirrors before students can confidently draw straight reflections. Research shows drawing ray diagrams by hand strengthens spatial reasoning more than software simulations alone.

What to Expect

Students will describe reflection using precise vocabulary like angle of incidence and reflection. They will sort mirror types by the images they create. Their ray diagrams will show accurate paths with labeled angles.

Watch Out for These Misconceptions

Common Misconception

During Mirror Image Stations, watch for students who assume reflected rays bend unpredictably.

What to Teach Instead

Ask them to trace the ray with a colored pencil and measure the angles with the protractor provided at each station. Have them share their measurements with peers to confirm the law.

Common Misconception

During Periscope Build, watch for students who place mirrors flat against the tube wall.

What to Teach Instead

Remind them to tilt the mirrors at 45 degrees so they can see the rule of equal angles in action, then adjust until the images align.

Common Misconception

During Multiple Reflections Demo, watch for students who think curved mirrors behave like plane mirrors.

What to Teach Instead

Have them sketch the ray paths on the whiteboard and compare the angles before and after each reflection to highlight the differences.

Assessment Ideas

Exit Ticket

After Mirror Image Stations, provide a worksheet with a plane mirror diagram. Ask students to draw the reflected ray and label the angles, then write the relationship between them in one sentence.

Quick Check

During Periscope Build, listen as students explain why their mirrors must be tilted at 45 degrees. Ask each pair to describe the size and position of the virtual image they see.

Discussion Prompt

After Multiple Reflections Demo, pose the prompt: 'If you wanted to hide a spy camera in a room using mirrors, which mirror type would you choose and why?' Let groups discuss and defend their choices based on the images they observed.

Extensions & Scaffolding

• Challenge: Ask early finishers to design a two-mirror system that bounces a ray across the room three times without touching the ceiling.
• Scaffolding: For students struggling with angle measurement, provide a transparent protractor overlay to trace rays directly on the mirror station surface.
• Deeper exploration: Invite students to research how parabolic mirrors focus light in telescopes and solar cookers, then present their findings to the class.

Key Vocabulary

Law of Reflection	A principle stating that the angle of incidence (the angle at which light strikes a surface) is equal to the angle of reflection (the angle at which light bounces off).
Angle of Incidence	The angle measured between an incoming light ray and the normal (an imaginary line perpendicular to the surface) at the point of contact.
Angle of Reflection	The angle measured between the reflected light ray and the normal at the point of contact.
Virtual Image	An image formed by light rays that appear to diverge from a point, but do not actually meet there; it cannot be projected onto a screen.
Real Image	An image formed by light rays that converge at a point; it can be projected onto a screen.
Concave Mirror	A mirror with a surface that curves inward, capable of focusing light rays to form real or virtual images depending on object distance.