# Flashlight Science: Transparent or Opaque?

### What You Need:

• White paper
• Flashlights
• Shapes cut from cardboard (square, triangle, star, and circle)
• Spring-type clothespin or strong paperclip
• Book
• Objects made of transparent, translucent and opaque materials ( See Step 8)

### What You Do:

1. While you are holding a white sheet of paper, your child's job will to be in charge of the flashlight, as the Official Flashlight Holder and your assistant. Tell him to not turn on the flashlight until you give the signal.
2. Without letting him see what you have in your hand, hold one of the cut out shapes so that it touches the back of the white paper. Clip on the shape with the clothespin or paperclip so that your hand doesn’t obscure the shape. Ask him if he can see what the shape is behind the paper.
3. Next, have him turn on the flashlight. Ask again if he is able to see the object behind the paper and guess what he thinks it might be?
4. Ask him to think about why he was able to identify the shape after the light was turned on. Discuss with him if he thinks the same experiment would work by putting the shape behind a book instead of a piece of paper? Try it to see. Encourage him to figure out for himself that light can pass through some things but not others.
5. Discuss his observations and introduce the terms opaque and translucent. Explain that objects (like books) that do not allow light to pass through are called opaque; materials (like paper) that allow some light to pass through are called translucent. Challenge him to name other objects that he thinks might be opaque or translucent.
6. Next, let him try shining the flashlight underneath his fingertips, then move the light down toward his palms. Ask which part of his hand he thinks is translucent? (his fingertips) Which part is opaque? (his palms)
7. Now, ask him to name a material that he can see through without a flashlight. Materials that let all of the light through, like glass, are transparent. Ask him if he can think of any other everyday materials that are transparent? Offer some examples, such as water or saran wrap.
8. Let him experiment with the objects you have collected, using a flashlight to determine which are transparent, translucent, or opaque. Transparent objects might include a glass jar, a clear or colored plastic glass bottle, clear or colored cellophane. Some toothbrush handles are transparent while others are opaque. Paper and most fabrics are translucent.

The important vocabulary words he'll be learning in this activity are more than just important vocabulary words: they are also fundamental scientific concepts that he will build upon later in the years to come. Soon you might find him with the flashlight on a regular basis, telling you all of the exciting new items he finds that are transparent, translucent and opaque!