Shadows
This Topic is About...
- I will investigate how light can pass through transparent materials and is blocked by opaque materials.
- I will sort materials into transparent or opaque groups.
- I will learn that shadows form when light from a source is blocked by an object.
- I will collect and record observations in tables, then interpret the results.
- I will make a prediction and see if it is right.
You’re going to be a science explorer!
Key Words
- dissolve
- insoluble
- soluble
- transparent
Tap to Learn the Meanings!
- dissolve: When a solid mixes completely into a liquid so it seems to disappear.
- insoluble: A substance that does not dissolve in a liquid.
- soluble: A substance that can dissolve in a liquid.
- transparent: Something you can see through clearly, like clean glass or water.
Great work! You’re learning key words about solutions and materials.
How are shadows made?
A shadow is made when light is blocked by an opaque object.
Light and opaque materials
Light cannot pass through an opaque material. This means that a dark area is made. This is a shadow.
Colour of shadows
Shadows have no colour. They are always dark.
Details in shadows
Shadows have no details like eyes or a mouth.
Shape and size of shadows
The shadow may not be the same shape and size as the object.
FUN QUESTIONS
1. Does everything have a shadow?
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2. Mia has two shadows. Why is this?
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3. If Mia moves, how might the shadows change?
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Transparent materials
Some materials are not opaque. They let light through. They are transparent. Transparent materials do not make a shadow. We can see things clearly through transparent materials.
FUN QUESTIONS
4. Glass is very good for making windows. Why is this?
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5. Why do shops use so much glass in their front windows?
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Be careful with glass. If it breaks it can cut you.
Think like a scientist – Opaque or transparent?
You will need: some different materials, a flashlight
Your task:
- Your teacher will give you some materials.
- Decide if you think each one is opaque or transparent.
- Write your prediction for each material.
- Shine a flashlight on each material. Does the light pass through?
- Record the result of your test for each material.
Suggested results table to draw:
- Column 1 – Material
- Column 2 – My prediction (opaque / transparent)
- Column 3 – Result of the test (opaque / transparent)
- First row example: glass – prediction: transparent – result: transparent
Thinking questions:
- Were your predictions correct?
- Which materials would not make good windows?
- Why would they not make good windows?
How am I doing?
- If you wanted to make a sunshade, would you use an opaque or transparent material?
- Which materials from your test might make a good sunshade?
Tap to see example answers
- Predictions vs results: Glass is transparent, so light passes through and it matches the prediction.
- Poor window materials: Cardboard, wood, thick plastic or metal are opaque so they block light and would not make good windows.
- Good sunshade materials: Opaque materials (e.g. card, fabric, wood) make good sunshades because they stop most of the light.
- Key idea: Transparent materials let light through; opaque materials do not let light through.