Preview · the opening missionRead this to the class:
After a storm, a rainbow stretches across the school field. "The Sun painted it," says one student. "No, the colours were inside the sunlight already," says another. The next day, at the school play, the lights go red for a scene and the green leaves on the scenery turn almost black. Nobody has touched them. "How can light change the colour of a leaf?" Your team's job: find the colours hiding in white light, then predict how coloured paper will look under coloured light.
Teams of three, with rotating jobs: Light Handler (holds the flashlight and filter), Observer (describes what they see), Recorder (writes it down).
Look inside the PDF
Sample pages, stamped “preview”. The download is the clean, full lesson.
In the full lesson PDF
- Predict (5–10 min)
- Hunt (20 min)
- Reveal (10–15 min)
- Act (10 min)
- Background for the teacher
- Assessment
- Student sheet
- Worksheet: Label it
- Worksheet: Try it at home
On the student sheet
- My prediction
- The band of colours
- What the squares looked like
- What we kept the same, and what we changed
- Lighting plan for the play
- Exit ticket
- Label it
- Try it at home
US Letter, prints cleanly in black and white. The student sheet is on its own page, ready to photocopy.
Free with an account (any 3 lessons), or US$19 / C$25 for all 3 lessons in this unit.
What students show by the end
- Records the evidence
- Explains white light
- Explains object colour
From the lesson’s rubric, which scores each one as not yet, getting there or got it.
Questions teachers ask
How long does “What colours are hiding in white light?” take?
55–65 min. Group size: teams of 3.
How much prep does it need?
20 minutes. Give each team a flashlight with a slit card (see lesson 1), an undamaged old CD or DVD, a white card, and squares of paper about 5 cm across in red, green, blue, yellow, white and black. Make two filters per team: fold clear red cellophane (or a coloured plastic report cover) into a double layer and hold it over the flashlight lens with a rubber band, and do the same with green. If you have an acrylic prism (plastic, not glass), put it with the CDs. The Hunt needs a dim room.
What materials do I need?
Small LED flashlight with slit card; undamaged old CD or DVD (or an acrylic prism); white card, about 15 x 20 cm; squares of coloured paper, about 5 cm; clear red and green cellophane or coloured plastic, in a double layer; rubber bands; and 1 more. Cost: about $15 for a class of 30 (less if you have flashlights and old CDs).
Which curriculum standards does it cover?
NGSS (US): 1-PS4-3 (partly) and MS-PS4-2 (partly). It also matches Cambridge Primary Science and Lower Secondary Science (not endorsed by Cambridge).
What’s in the lesson PDF?
A teacher guide that walks you through predict, hunt, reveal, act, background for the teacher and assessment, then a student sheet (“My prediction”; “The band of colours”; “What the squares looked like”; “What we kept the same, and what we changed”; “Lighting plan for the play”; “Exit ticket”; “Label it” and “Try it at home”) on its own page, ready to photocopy. It’s US Letter and prints cleanly in black and white.
Can I try it for free?
Yes. A free account includes any 3 full lessons of your choice, and this can be one of them. After that, this unit is US$19 (C$25) for all 3 lessons, yours to keep, or every lesson is US$79 (C$109) a year.