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See-Through, Cloudy or Blocked

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No sign-up and no real names. In the lesson you check your understanding as you read, run the experiment yourself, and practise until it sticks.

Clear, cloudy or blocked

Shine a torch at a clear glass window. The light goes right through, so the glass is see-through. Scientists call it transparent. Now shine it at wax paper. Only some light gets through, and things behind it look fuzzy. That is translucent. Cardboard lets no light through at all. It is opaque, and it makes a dark shadow.

Choosing the right material

We choose materials for the light they let through. Windows are transparent, so light comes in and we can see out. Bathroom windows are often translucent. Light gets in, but nobody can see in clearly. Thick curtains are opaque, so they keep a bedroom dark for sleeping. A mirror is opaque too, but it bounces light back instead of soaking it up.

Curriculum links: NGSS 1-PS4-3