A basic concept in science is the idea that all things in the world are transparent, translucent or opaque (in other words, light passes through them easily, some light passes through them, or little to no light passes through them). Objects and substances fall under one of these labels based on how closely their atoms and molecules are arranged. Young students just learning this idea need activities in order to understand the three terms.
The teacherfiles.com education and lesson plan website presents a charting activity for those learning about transparency, translucency, and opaqueness. After the teacher explains to the students what the terms mean, students create charts. On the left side of the chart are any objects the teacher wants to use to demonstrate the terms. To the right are columns labelled "transparent," "translucent" or "opaque." The teacher challenges the students to identify which objects are transparent, translucent or opaque, and the students record their identifications on their charts. Variations of this idea are easy to do. For example, instead of charting, students could put all of the translucent objects together in a pile, the transparent objects in another pile and the opaque objects in a third pile.
Victoria Hoffman came up with a simple activity to teach transparency, translucency, and opaqueness that uses a flashlight. Her concept is that kids love playing with flashlights and therefore will enjoy being able to learn with one. She suggests having a child be your "assistant" and official flashlight holder. You have them shine a flashlight toward a piece of paper. As they do this, you put different shapes or objects behind the paper and have the child identify them. You then ask the child if they think they'll still see the shapes and objects if you shine the light against other objects, such as a book. As you try out different objects, you discuss the three terms (transparent, translucent and opaque) and talk about what they mean.
Only transparent objects will not produce some kind of shadow. Opaque objects produce the darkest shadows. One activity that is appropriate for very young children is to set up a bright light in the room, getting the rest of the room as dark as possible. The children simply place objects in front of the light to discover which objects create shadows and which ones block light most completely. As this is done, you can have the children place all the similar items together. The activity thus also is appropriate for teaching how to compare. An alternative using this concept is to do a "puppet show" with simple objects that serve as "characters" that may be categorised as translucent, transparent or opaque. A cute plot for such a play might be that one of the characters doesn't know for sure if light goes through him, and the other characters help him find out.