What Causes a Rainbow? — Reading Comprehension

Grades

About This Reader

This NGSS-aligned middle school science reading passage explores how rainbows form through the bending and reflection of sunlight in water droplets. Students will learn how sunlight contains all colors and how each color bends at a slightly different angle through the process of refraction. The passage also explains how rainbows appear as arcs and why they are seen when the sun is behind the observer. This activity supports NGSS standard MS-PS4-2, helping students understand light behavior and visible phenomena in nature while improving science reading comprehension.

CONTENT PREVIEW

A rainbow is one of the most colorful and beautiful sights in the sky. It appears when sunlight shines through water droplets in the air, usually after it rains. But how does light turn into a rainbow of colors? The answer lies in how light bends and reflects.

Sunlight may look white, but it is actually made up of many different colors—red, orange, yellow, green, blue, indigo, and violet. When sunlight enters a water droplet, it slows down and bends. This bending of light is called refraction. Each color bends a little differently because of its wavelength, which is why the colors spread out.

Inside the droplet, the light bounces off the back and travels back out, bending again as it leaves the droplet. This second bending helps separate the colors even more. The process of light bouncing inside the droplet is called reflection.

When millions of water droplets reflect and bend sunlight at the same time, a circular arc of colors appears in the sky. The colors always follow the same order: red on the outside, and violet on the inside.

You can only see a rainbow if the sun is behind you and the rain is in front of you. Rainbows are most common in the morning or late afternoon, when the sun is lower in the sky.

Fun Fact: A rainbow is actually a full circle, but from the ground, we can only see the top half. From an airplane, you might see the whole circle!

When does a rainbow usually appear?

During the nightOn snowy daysAfter it rains and the sun shinesWhen the wind is strong

What is sunlight made of?

Only red and blue lightAll the colors of the rainbowJust white lightWater and air

What causes light to bend when it enters a droplet?

Heat from the sunWind pushing itRefractionEvaporation

What happens to the light inside the droplet?

It disappearsIt reflects off the backIt freezes into iceIt turns into color

Why do the colors spread out in a rainbow?

Because water is heavyBecause each color bends differentlyBecause light travels in circlesBecause the air is hot

Why is the sun's position important for seeing a rainbow?

The sun has to be directly aboveThe sun must be behind youThe sun should be hiddenThe sun must be next to you

What is the main idea of the passage?

Rainbows form from wind and fogRainbows are rare and magicalRainbows are caused by light bending and reflecting in raindropsRainbows are just colored clouds

Why might someone in an airplane see a full circle rainbow?

They are closer to the cloudsThey are above the ground and can see the whole shapeThe airplane makes the rainbowThe sun is brighter in the sky