Theory:

Transparent materials are substances or materials that allow things to be seen through them.
Example: Glass, pure water, air, some plastics
 
Note: When water is cooled, it transforms into ice, which is not transparent or opaque.
 
We use a lot of transparent materials in our everyday lives, including eyeglasses, window panes and light bulbs.
 
You may have noticed that in stores such as bakeries, edible products are kept in transparent glass so that customers can easily see them.
 
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Transparent bottles
However, there are some objects that we are unable to see through. These materials are called Opaque.
For example we cannot tell what is inside a closed wooden box, a cardboard carton or a metal container from the outside. These are the materials called opaque materials.
 
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Let us do an activity:

Step 1: Take a sheet of paper.

Step 2: Add a few drops of oil to the piece of paper.
 
Step 3: Oil should be evenly distributed throughout the paper.
 
Step 4: Look through the paper at a lighted bulb.

Is it possible for you to see the light clearly?
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The materials that allow objects to be seen but not clearly called Translucent materials.
Example: Sunglass and frosted glass.
 
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 Sunglass and frosted glass are translucent materials.
 
As a result, we can also group materials as transparent, translucent or opaque.
 
What did we learn from this chapter?
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  • Materials differ in their appearance.
  • Materials differ in the way they mix in water or other liquids.
  • In water, they may float or sink.
  • Materials can be transparent, opaque or translucent.
Materials can be grouped based on similarities or differences in their properties.
 
What is the purpose of sorting materials into grouping?
  • It is easier to study the materials' properties.
  • To look for similarities/patterns in their properties.