Summary
Overview
In this lesson, students explore firsthand what transparent, translucent, and opaque mean, and how they are related to light. They will place a variety of materials in front of an illuminated object and predict if and how well they will be able to see the object through the material sheet. In doing that, students will realize that different materials allow different amounts of light to pass through.
Remote learning: This lesson plan can be conducted remotely. The Engage section of the lesson can be done over a video call, then students can work individually and independently during the Explore section, using the Student Worksheet as a guide. A set of materials can be prepared in advance or students can use materials found around the house. End the lesson with discussion over a video call during the Reflect section.
Learning Objectives
- Explain the difference between translucent, transparent, and opaque materials.
- Conduct an investigation to find out if a material is translucent, transparent, or opaque.
NGSS Alignment
This lesson helps students prepare for these Next Generation Science Standards Performance Expectations:- 1-PS4-3. Plan and conduct investigations to determine the effect of placing objects made with different materials in the path of a beam of light.
| Science & Engineering Practices | Disciplinary Core Ideas | Crosscutting Concepts | |||
| Science & Engineering Practices | Planning and Carrying out Investigations.
Make observations (firsthand or from media) and/or measurements to collect data that can be used to make comparisons.
Analyzing and Interpreting Data. Compare predictions (based on prior experiences) to what occurred (observable events). Engaging in Argument from Evidence. Construct an argument with evidence to support claim. |
Disciplinary Core Ideas | PS4.B: Electromagnetic Radiation.
Some materials allow light to pass through them, others allow only some light through and others block all the light and create a dark shadow on any surface beyond them, where the light cannot reach. |
Crosscutting Concepts | Cause and Effect.
Simple tests can be designed to gather evidence to support or refute student ideas about causes. |
Materials
For each student group of 2-3:
- Cardboard tubes, such as a toilet paper roll or paper towel roll
- Rubber band
- 3 different, small, opaque objects, such as a toy car, rubber ducky, action figure, plastic animal, etc.
- Sheets of several transparent, translucent, and opaque materials (same for each group)
- At least 2 different transparent sheets (plastic wrap, plastic baggie, glass from a picture frame)
- At least 2 different translucent sheets (parchment paper, wax paper, frosted plastic sheet, tissue paper, white printer paper)
- At least 2 different opaque sheets (cardstock paper, cardboard, wood, dark-colored construction paper)
For teacher:
- Bag to hold the objects
- Drinking glass
- Frosted plastic cup
- Ceramic cup
- Flashlight
Background Information for Teachers
This section contains a quick review for teachers of the science and concepts covered in this lesson.We can categorize materials by their appearance, like transparent, translucent, or opaque; dark or light colored; glossy or matte finish, etc. These classifications are based on how the materials interact with light that shines on them. Materials can transmit, absorb, scatter, or reflect light.
When a material transmits light, it allows light to pass through. Materials that let all or most of the light pass through are called transparent (Figure 1, right). Transparent materials themselves appear clear, which is why you can clearly see any object behind a transparent material. A translucent material also allows light to pass through, but the transmitted light is scattered in all directions (Figure 1, middle). Although you can see through a translucent material, the scattering of the light results in a blurry image of any object that is placed behind a translucent material. Even if the object itself is not clearly visible, you will still be able to see light as brightness through a translucent material. Opaque materials do not let any light pass through (Figure 1, left). Some of these materials look dark and tend to get warm when left exposed to light. Others reflect most or some of the incident light. As a result, it is not possible to see through an opaque material; the only thing you will be able to see is darkness.
The left image shows a black rectangle, which represents an opaque material. Yellow arrows pointing toward the black rectangle from the left symbolize the incident light. No arrows are seen on the right side of the black rectangle. The middle image shows a grey rectangle, which represents a translucent material. Yellow arrows pointing toward the black rectangle from the left symbolize the incident light. On the right side of the rectangle, yellow arrows are pointing away from the grey rectangle in random orientation. The right image shows a white rectangle which represents a transparent material. Yellow arrows pointing toward the black rectangle from the left symbolize the incident light. On the right side of the white rectangle, the yellow arrows point straight to the right in the same angle as on the left side.
Figure 1. Illustrations of light absorption (left), scattered light (middle), and transmitted light (right).
However, no common material exists that transmits or absorbs all light. For example, even though window glass looks clear to us, it still reflects a little bit of light. Also, we would not be able to see materials that absorb all light; we would only see the absence of light. This is shown in this super-black coating demonstration.
In this lesson plan, students will investigate a variety of translucent, transparent, and opaque materials. Specifically, they will test if they can see an illuminated object through a material and assess the object's appearance. In doing so, they will realize that different materials have different optical properties. Based on their observations, they will then classify the materials based on how much light they let pass through them.
