Transparent, translucent or opaque?
Shine a torch through different materials, see how much light passes, and sort them into transparent, translucent and opaque.
Core concept
In short: Shine light on materials to see which let light through and which make shadows.
Transparent materials let almost all light through, translucent materials let some through, and opaque materials let none through and cast shadows
Topic: Light
Light travels in straight lines. When it meets a material, it may pass through, be scattered, or be blocked. A transparent: Lets almost all light through, so you can see clearly through it, like glass. All key words material lets almost all the light pass straight through, so you can see clearly through it. A translucent material lets some light through but scatters it, so things behind it look blurred. An opaque: Lets no light through, like wood or a book. All key words material lets no light through: it blocks the light and casts a dark shadow: A dark shape made where an object blocks the light. All key words.
What you will learn
- Test materials by shining light through them.
- Classify materials as transparent, translucent or opaque.
- Choose suitable materials for windows, curtains and lampshades.
Before you start
- Know that we see objects when light from them enters our eyes.
Materials
- Clear glass, clear plastic, water in a clear jar, tracing paper, oiled paper, frosted glass, thin white cloth, wood, cardboard, steel plate, a mirror, a stone
Equipment
- Torch, white screen
Procedure
- Choose a card and shine a torch through the material onto a screen.
- Check whether you can see the torch clearly, see only a glow, or see a shadow.
- Place each card in the right group.