Science Experiments: Learning All About Light

by admin

Science is one of those subjects you either really love teaching, or don’t. Maybe you didn’t enjoy it in school when you were younger, or maybe you are having a hard time finding ways to keep your kids engaged. If that is you, I hope this post helps! This will be the first of a series of posts I plan to write–all about fun, engaging experiments! I have learned SO much teaching my kids. Don’t shy away if you don’t feel confident to teach something. Learn right along with them!

This post contains affiliate links, which means if you choose to purchase products linked in this post I will receive a tiny commission, which helps keep this blog up and running :]

We kicked off the school year learning all about LIGHT.

How light allows us to see things is such an amazing process, and it begins with reflection.

Experiment #1 – Reflection

What you need: Handheld mirror, flashlight, and a dark room

Go into the dark room and point out that you can’t see anything because there is no light. Then, turn on the flashlight. Put the end of the flashlight (the opposite end the light is shining out of) up against the wall so the flashlight is parallel with the floor and shining directing across the room to create a circle of light. Hold your mirror in the beam of light (just a foot or two away) so the light is shining directly on the mirror. Wait! Where did the circle of light go? While keeping the flashlight still, tilt the mirror up and down and side to side slowly and notice what happens to the beam of light.

Discussion: What direction was the light traveling when you pointed it across the room? [Straight.] What happened to the light when it hit the mirror? [It bounced back straight towards the flashlight.] What happened when the mirror was tilted in different directions? [The light bounced off of the mirror and went in a different direction.] Why is this important? In order for us to see things, light has to reflect, or bounce, off of it and hit our eyes. When you were standing in the dark room with no light, there was no light bouncing off of objects so you couldn’t see anything. Once the flashlight turned on, you were able to see because the light was reflecting off of the objects in the room.

Experiment #2 – The Colors in Light

What you need: a CD, a flashlight, a white piece of paper, tape and a dark room

Go into the dark room and turn on the flashlight. Tape the paper onto the wall. Shine the flashlight onto the bottom of the CD so it reflects a rainbow of light onto the white paper.

Discussion: Where did the rainbow colors on the paper come from? The kids will probably say the CD, but it actually came from the light! The CD separates the color in the light so you are able to see them on the paper!

You can also use a prism to split light and separate the colors. I actually used one of my chandelier crystals and it worked great

Experiment #2a – Creating a Rainbow

What you need: a hose and a sunny day

Go outside and stand with your back to the sun. Spray the hose and a rainbow will appear!

Discussion: Where did the rainbow come from? [The light.] The water droplets in the air split the light, allowing us to see all the colors of the rainbow!

Experiment #3: Light Reflecting and Absorbing Color

What you need: 2 sheets of white paper, a sheets of black paper, a sheet of red paper, a flashlight, and a dark room

Turn the flashlight on and hold a sheet of white paper behind the flashlight. You will be able to see the paper because the light is bouncing off of the walls and objects in the room, however you probably won’t see it very well. Now have your child take the second piece of paper and hold it in front of the flashlight. What happened? You can see the paper behind the flashlight much more clearly! Now, remove the paper in front of the flashlight and replace it with a black paper. What happened? You can’t see the white paper behind the flashlight very well. Now, remove the black paper and replace it with the red paper. What happened?

Discussion: When the white paper was in front of the flashlight, what happened to the paper behind the flashlight? [It lit up because the light reflected off of the white paper onto the other paper.] What happened when the light was hitting the black paper? [The white paper was hard to see because the light was being absorbed by the black paper.] What happened when the light hit the red paper? [All the colors in the light were absorbed by the red paper, except for the color red. That red color was reflected onto the white paper, making it look red.]

Experiment #3a: Light Reflecting and Absorbing Color

What you need: a white garbage bag, a black garbage bag, a window with direct sunlight, scissors, tape

Tape a large piece of each garbage bag onto the window and let it sit there for 10 minutes. After at least 10 minutes, have your child touch each bag.

Discussion: What did the white garbage bag feel like? [warm.] What did the black garbage bag feel like? [hot.] We know that black objects absorb light, while white objects reflect light. This is why you don’t want to wear a black shirt on a hot day! Light is a form of energy, called radiant energy. Energy cannot be created or destroyed, but it can be changed or converted into another form of energy. So, the radiant energy from the sun was absorbed by the black bag, and it was converted into thermal energy (heat), which we can feel when we touch it.

We journaled about the four types of energy

Experiment #3b: Light That Is Reflected and Absorbed

What you need: a magnifying glass, a newspaper with white and black spaces, a baking sheet, glass of water (just in case), a sunny day, adult supervision

Put the newspaper on the baking sheet in direct sunlight. Hold the magnifying glass above the newspaper, so that the light shining through it is on a white space on the newspaper. Move the magnifying glass closer and further away until you get a small circle of light. What happened? The newspaper should start to smoke and burn. Remove the magnifying glass and do the same thing on a black space on the paper. What happened? The paper will start to smoke and burn almost instantly. Use the glass of water if the burning gets too large.

Discussion: We know that the newspaper absorbed the light, and the radiant energy from the sun was converted into thermal energy when the newspaper started to burn. Did the magnifying glass increase the amount of energy hitting the newspaper? [No, but it concentrated it into a tiny circle, thus causing it to burn.]

Experiment #4: Converting Mechanical Energy to Radiant Energy

What you need: Florescent bulb, balloon, and a dark room

I wish I had a picture of this one. It’s so fun! Blow up your balloon and tie off the end. Get it nice and charged up with static electricity. Your kids will love getting it rubbed all over their hair, haha! Then, hold the bulb in one hand closely under the balloon, but not touching. With the ballon facing down and its tail pointing up, move the balloon quickly back and forth above the bulb. You should see small flickers of light come from the light bulb.

Discussion: We know energy can’t be created, so where did the light come from? [the balloon!] The balloon was using mechanical energy by moving all around. Since the electrical charges from the balloon are attracted to the electrical charged in the bulb, that energy was converted into radiant energy, causing the lightbulb to light up.

Experiment #5: Refraction – The Bending of Light

What you need: Clear glass or plastic container, water, pencil or a similar object with a straight shape

Fill the glass or container with water to about three-quarters full. Observe the appearance of the pencil when it is placed next to the glass but not submerged in water. Notice its size and position. Gently place the pencil into the water at an angle. Let a part of it remain outside the water. Look through the side of the glass and observe how the pencil appears to bend at the water’s surface. Challenge the kids to experiment with different objects or try varying the angle at which the pencil enters the water. Discuss how the amount of bending changes with different factors.

Discussion: What happened when we put the pencil in the bowl of water? [It appeared to bend.] Actually, the pencil didn’t bend at all! It was the light traveling through the water! When light travels from air to water, it bends. This bending of light is called refraction. The pencil appears to be bent at the water’s surface because light travels at different speeds in air and water.

I hope these experiments were helpful and make for some fun learning days for you and your kids! Stay tuned for my next post, where I will feature experiments all about air and water.

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