Try This Remarkable Refraction of Light Lab

Teaching refraction of light in upper elementary? Try this simple (but remarkable) lab. Kids explore three situations where water bends the rays.

Refraction of light is clear to see in three simple labs.

Ms. Sneed Prepares Her Refraction Station

Our favorite fourth grade teacher sat at the side table with her teaching partner. “Let’s continue planning our light energy unit. Today we’ll tackle refraction of light. Additionally, kids will work with four more concepts:

“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 two cups, a pencil, a penny, some wax paper, a beaker of water, and an eyedropper.

“The materials for this refraction of light labs can be found in any classroom or home,” she said. “Love it.”

Once she’d placed them on the table, the pair began.

Pencil in a Cup of Water – Refraction of Light Lab 1

“For the first activity,” Mr. Frank said, “kids pour water into a clear cup. Then the prop the pencil in the cup.”

He placed the cup in front of him and did just that.

Ms. Sneed stared at the cup from the side. “After all these years, I still can’t get over it. When I look at the pencil, it appears to be cut in two. Amazing. This refraction of light lab is a must-do for any elementary energy unit.”

To illustrate refraction of light, try this simple lab. Simply stick a pencil in a clear cup that's partially filled with water.
Are you feeling “pinspired”? Feel free to pin images from this post.

Penny in a Cup – Refraction of Light Lab 2

Next, Ms. Sneed grabbed a red cup and placed a penny inside it. “This one is a little tricker,” she said. “Let’s try it.”

After placing the cup on the table, Ms. Sneed stood up and backed away from it. “Okay, I’m far enough away that I can’t see the penny. The lip of the cup blocks my view. Now,” she directed Mr. Frank, “slowly pour water into the cup.”

As he poured the water, Ms. Sneed stared intently at the cup. Before long, she cried out, “I see it! The water refracted the rays, allowing me to see the penny from the same location.”

“If I remember correctly, this refraction of light lab doesn’t always work the first time,” Mr. Frank said.

“Yes, I’ve had problems with kids moving the cup, jostling the penny, or even the person moving. In the end, I just tell them to try again. But, of course, when it works, this little experiment is like magic!”

To illustrate refraction of light, try this quick lab. Put a penny in an opaque cup. Then back away from it until you can no longer see the penny. Ask someone to pour water in the cup, and the penny magically appears!

Water Drop on Wax Paper – Refraction of Light Lab 3

“For the last refraction of light lab,” Mr. Frank said, “we need only a sheet of wax paper and a drop of water.”

He grabbed the lab sheet and laid it on the table. Over it, he placed the wax paper. Then, using the eyedropper, he squeezed a drop of water onto the wax paper. Positioning the drop over a few letters, the pair could see that they were magnified.

“Bigger,” said Ms. Sneed. On cue, Mr. Frank added some water to the drop.

“Ah yes, a bigger drop magnifies even more!”

A simple drop of water on a piece of wax paper illustrates refraction of light. In this lab, kids begin to see how lenses work.

Enjoy Teaching Light

Ms. Sneed sat back in her chair. “I love this set of light activities. Five stations let kids explore concepts with simple activities.”

Mr. Frank nodded and smiled. “For each of these stations, students become totally engaged – and I love how they can work independently. It makes my job so easy and fun.”

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