Light and materials
Think about the materials we looked at: plastic, stone, paper, wood, cardboard.....
Now think about light.
What happens when you shine a light on these materials?
Does the material allow the light to go through, so that you can clearly see the things behind it? (Is the material transparent?)
Or does the material block the light, creating a shadow behind it? (Is the material opaque?)
Find pieces of different materials and ask your parents for a torch. Shine a light on each one and say whether the material is transparent or opaque.
When I shine the torch at a sheet of plastic, I can clearly see the ball behind.
The plastic is transparent.
When I shine the torch at a paper envelope, it blocks the light and creates a shadow behind, so I cannot see the part of the ball behind the envelope.
The paper is opaque.