Light Behaviours

Overview

Students investigate how light interacts with different materials and surfaces through absorption, reflection, refraction and scattering. They use a planned procedure to gather reliable evidence and then communicate conclusions using scientific language, including learning from and evaluating YouTube explanations.

Learning intentions

• Students will follow a planned, safe procedure to test how light behaves with common materials.
• Students will describe observable features of light interactions: absorption, reflection, refraction and scattering.
• Students will use evidence from observations to explain patterns in results.
• Students will evaluate the reliability of YouTube science explanations and use them to refine their own understanding.

Success criteria

• I can correctly identify which interaction is occurring (absorption, reflection, refraction or scattering) and justify it with evidence.
• I can record measurements/observations clearly enough that another student can repeat the method.
• I can use key terms accurately in a short explanation or claim-evidence-reasoning.
• I can identify at least one strength and one limitation of a YouTube source based on evidence quality.

Curriculum links

• SC5-WS-04 — Students follow a planned procedure to undertake safe, ethical, valid and reliable investigations.
• SC5-WAM-01 — Students describe the features and applications of different forms of waves (including light wave interactions).
• SC5-WS-05 — Students select and use a range of tools to process and represent data.
• SC5-WS-08 — Students communicate scientific arguments with evidence, using scientific language and terminology.

Lesson structure (60 minutes)

1. 0–6 min · Hook with misconceptions. Teacher displays the investigation and light interactions slides showing two images: a flashlight through a clear container vs a frosted container, plus the prompt “Why does the beam change?” Students quick-write: which interactions they think are happening and why (no answers yet—just predictions).

2. 6–14 min · Direct teach (mini-lesson). Teacher uses the investigation and light interactions slides to summarise four interactions with simple diagrams and examples:

• Reflection (angle-of-incidence idea, visible bounce)
• Refraction (bending when entering/exiting different media)
• Absorption (dimmer/less transmitted light)
• Scattering (beam spreads in directions) Students add a one-sentence “definition + observation” for each interaction in the worksheet notes space on the light interactions investigation worksheet.

3. 14–22 min · Safety + planned procedure. Teacher sets up materials and demonstrates one safe setup while referencing the investigation and light interactions slides: stable bench, controlled light source, avoid looking directly at the torch, handle lenses/prisms carefully, and repeat each test at least twice. Students listen, then check the procedure steps and record any teacher “do/don’t” on the light interactions investigation worksheet.

4. 22–40 min · YouTube-informed investigation (stations, evidence collection). Teacher divides class into small groups and assigns a quick “learning sprint” for each interaction using YouTube (no links shared by the teacher; students search on school devices for videos that show the same interaction). Teacher prompts with the investigation and light interactions slides:

• Group A: absorption (different coloured/black/white paper or fabric)
• Group B: reflection (mirror-like surface vs matt surface; observe beam visibility)
• Group C: refraction (glass/plastic blocks or aquarium/water + pencil “bending” demo model)
• Group D: scattering (water with milk, frosted acrylic, tissue over beam) Students: (1) watch 2–3 minutes from a selected YouTube video, (2) decide what observation they should expect, then (3) run the station procedure and record results in the light interactions investigation worksheet (include at least one qualitative observation and one simple representation such as a labelled sketch or “more/less/most”).

5. 40–48 min · Reliability check (source critique). Teacher pauses on the investigation and light interactions slides with a 3-point checklist displayed:

• Does the video show evidence (what is measured/observed)?
• Does the explanation match the visible result?
• Are sources/claims reasonable and not oversimplified? Students, in pairs, choose one YouTube video they used and complete the “strength/limitation” box on the light interactions investigation worksheet (no need for exact channel names; focus on evidence quality).

6. 48–58 min · Communicate scientific argument (CER). Teacher returns to the investigation and light interactions slides and models a short claim-evidence-reasoning sentence structure using light interaction terms. Students write one CER paragraph on the light interactions investigation worksheet for their station:

• Claim: which interaction(s) occurred
• Evidence: what they observed (and a sketch/notes)
• Reasoning: connect observation to the wave interaction (e.g., scattering “spreads” the beam; absorption “reduces” transmitted light)

7. 58–60 min · Exit reflection. Teacher collects the light interactions investigation worksheet and displays one final prompt on the investigation and light interactions slides: “Which interaction surprised you most and what evidence changed your thinking?” Students answer in 1–2 sentences as they hand in.

Resources

• the investigation and light interactions slides
• the light interactions investigation worksheet (one per student)
• Torches or phone flashlights (one per station)
• Assorted materials: white paper, black paper, coloured paper, matt vs shiny surfaces, mirror (where available)
• Transparent blocks or clear plastic pieces; shallow water container; possibly a clear “lens” or acrylic sheet for refraction demonstration
• Scattering materials: frosted acrylic/tissue; small cups of water with milk (or pre-made scattering medium)
• Rulers/protractors (optional for angle notes), measuring tape (optional), sticky labels
• Safety glasses if available (especially for groups handling liquids/lenses)
• Devices for searching YouTube and viewing short clips (teacher-managed, school appropriate settings)

Assessment

• Formative: teacher checks group evidence notes during station work (valid observations, repeated trials, correct interaction terminology).
• Formative: collect and review the YouTube reliability checklist for evidence-based reasoning.
• Summative (within lesson): evaluate CER paragraphs on the light interactions investigation worksheet for claim-evidence-reasoning using scientific language.

Differentiation

• Provide sentence starters on the light interactions investigation worksheet: “The light shows scattering because…”, “My evidence is…”, “This suggests…”
• Support students who need structure by assigning each student a specific recording role (sketch/labels, observations, reliability critique).
• Offer an extension within the same task: students identify which interaction is dominant and which is also occurring at a lower level (e.g., reflection plus absorption on matt surfaces).
• For EAL/SEN: allow diagrams and labelled sketches as primary evidence; keep vocabulary to the four interaction terms plus “transmitted/absorbed/spread/bent”.