Just Passing Through
Lesson 8 of 11
Objective: Students will be able to determine the difference between opaque, transparent, and translucent materials using a light source.
Our centering question today will be, "What happens when light passes through materials that scatter it's straight path?"
I will ask the students to turn and talk to their shoulder partners about whether or not they think light passes through objects, or if it always reflects.
When students gather, I will show them what happens to light when it hits a book. I am expecting everyone to predict that it will be blocked and will cause a shadow. I will then tell them that the book is called an opaque object because it blocks all light. Next, I will test our prediction. We will then put the term on the Light Bulb of Information chart.
Next, I will ask students to tell a shoulder partner what their predictions will be for light hitting a plastic grocery bag and a clear glass vase/glass. After investigating the outcome, I will add the terms and definitions translucent and transparent to the chart.
When the students have an idea of these terms, I will ask them to predict if all, some, or no light will pass through various objects that I have put in a chart for them. I will then test the objects for the class and the students will confirm their predictions.
Student teams will be given a flashlight and sent out into the school with strict norms on how to conduct investigations outside of the classroom. They are:
- Stay together
- Only conduct the experiment
- Stay indoors
- Do not go into other classrooms
- Quiet voices
- Return to the class at a specific time
As students explore, I will tour the school as well, in order to observe and question. Many of my questions will be about their predictions, correct use of vocabulary terms, and what they think might make a difference in light passage through materials.
This student's prediction was correct and all I had to do with him was work through the term to use when communicating the outcome. He also was building a theory about the thickness of a material and the response of light to it.
These girls worked with a green flag and were able to discuss with me the idea of color possibly being a determinant of how light passes through. In this clip, they had a lot to say and I talked to much! See my reflection below on this common mistake. However, the girls were working well together to gain evidence of their theory.
As I approached this student, he was struggling to determine where the light was. He was convinced this object must be translucent and was not going to give up until he proved it! The problem he was having was that he was shining the light from the fattest part of the cone and then trying to locate the light that was being dispersed inside the cone. Then, he realize he could test the material a different way. With perseverance, he was able to confirm his prediction!
Sharing and Closing
As a closing, the students were asked to first gather with a nearby team and share their most surprising results. Then, as a class, we shared those thoughts and discussed why we were surprised.
This girl shared that she was surprised that the window to a dark office was transparent, as she thought that because there was no light shining in the room from the hallway lights, that her flashlight would not make a difference. This caused a discussion to start about ceiling lights and how their lights shine down in a straight line and couldn't get into the window. Interesting thought!
After sharing our investigations, I asked the students what type of material should be used to create a pair of sunglasses and why. I also asked them what materials should be used to build a movie room.