Try this reflection of light experiment with your kids. It’s easy! Just grab a flashlight and some everyday objects. Then ask kids to reflect the beam onto the wall.
Ms. Sneed Prepares Her Reflection of Light Experiment
Our favorite fourth grade teacher sat at the side table with her teaching partner. “Let’s continue planning our light energy unit. Next up: reflection of light. It’s another science station, so kids will work in their lab groups.”
“Okay, I’ll pull up the lab sheet,” Mr. Frank replied.
Gathering the Materials
As usual, Ms. Sneed headed toward the science cupboard. Before too long, she returned with a flashlight and a baggie full of everyday objects.
“What do we have here?” she said as she dumped the contents of the bag. “Yep, some shiny, some dark or bumpy, and some in between.”
Mr. Frank chuckled. “Looks like everything but the kitchen sink. But seriously, what an easy lab! With just a flashlight and some random materials – all found right in our classrooms – we can conduct this simple experiment.”
“Yes, and keeping it in a baggie from year to year saves us a bundle of time.”
Positioning the Flashlight
“Hmm,” said Mr. Frank. “I can’t remember exactly how this reflection lab goes.” He picked up a Christmas ornament and the flashlight. Then he walked toward the wall.
“I know that we shine the beam on the object.” He turned on the flashlight. Holding the ornament directly in front of him, he shone the light on it. Unfortunately, the beam bounced off the ornament and onto his dark sweater, where it was absorbed.”
“No,” Ms. Sneed giggled. “Let me show you.” Without a beat, Mr. Frank handed her the flashlight and ornament. Then, as she stood perpendicular to the wall, Ms. Sneed trained the flashlight beam so that it bounced onto the side of the ornament and onto the wall.
“Aha. You shone it almost straight at the wall but with the ornament in between. Maybe at a 140 degree angle? Obviously, I’ll have to model this for my students. Otherwise, they’ll spend too much time figuring it out.”
“Good idea. In my opinion, the actual angle doesn’t matter. Just so the beam bounces onto the wall. That way, kids can analyze how much light actually reflected off of the object.”
Categorizing Reflection of Light
Mr. Frank looked at the screen of his laptop. “The reflection lab sheet has three columns. For the first, kids list stuff that reflects. In other words, all or most light bounces back. For the second, they write objects that partially reflect. And in the third, they place items that absorb.”
Experiment with Reflection of All (or Most) Light
As Ms. Sneed picked through the pile of objects, she pushed shiny things to the side. “When the flashlight shines on the CD, mirror, metal lid, and ornament, all or most of the beam will bounce onto the wall.”
Mr. Frank nodded. “At the bottom of the page, kids have to list words that describe objects that reflect all or most light. Looking at these objects, I’d say ‘shiny.’ What other words could they use?”
“Words like ‘smooth,’ ‘dense,’ and ‘hard’ would also work.”
Experiment with Reflection of Some Light
Next, Ms. Sneed pulled out items that had a little – but not much – luster: a piece of Styrofoam, a plastic lid, and a base-ten block. “For this reflection of light lab, I’d say these fall into the partial column.”
Mr. Frank looked at the remaining items. “Hey, what about this hand lens? It’s dense and smooth, but when the beam hits it, part of it will pass through. That will really make kids think.”
As he spoke, Ms. Sneed picked up a white paper plate. “Hmm, I suppose this will also go in the middle column. Some light will reflect when the flashlight beam hits it.”
Experiment with Absorption of Light
Both teachers looked at the remaining items in the pile: a wadded up piece of paper towel and a sock.
“Because they are bumpy and porous, these should absorb. But as they experiment with reflection of light, kids could argue that a little bit bounces off of them – especially if we darken the room. Additionally, our students may already know that white tends to reflect while black absorbs,” said Mr. Frank.
“Hmm, both of these objects are white. Let’s add a piece of black fabric or a black sock to the bag.”
“Can we take this a little farther? To really make them think, let’s also add something black that’s smooth and has some luster. You know, like a black pool ball or a mini chalkboard. That way, they will find out that a variety of conditions allow light to be absorbed.”
“Great idea,” said Ms. Sneed, “because objects that totally absorb are dark and bumpy.”
The two teachers looked at each other and smiled. Oh how they loved making kids think!
Extending Reflection of Light Lab
“In this physical science activity,” said Mr. Frank, “kids will also rotate through centers that explore characteristics of light, opacity, refraction, and color. If kids finish this station early, they can experiment with reflection of light with objects around the room.”
“Great!” Ms. Sneed responded. “I love this set of light activities. It lets kids experiment with reflection of light – and more.”
“Not only that,” her teaching partner responded. “They also work independently and become totally engaged.”