Light Lesson Exam Study Guide (5th Grade)

A rainbow is most likely to be observed at which time?

5:00pm

What is the electromagnetic spectrum?

A collection of different types of electromagnetic radiation

Red light is to white light as a tree is to:

A forest

What device produces light by running an electric current through a gas?

A neon sign

What could you use to split white light into its component colors?

A prism

What does a prism do to light?

A prisms can be used to break light up into its spectral colors. (The colors of the rainbow)

What is a shadow?

A shadow is the dark area you see on a surface when an object between the source of the light and the surface blocks or absorbs all the light. No light reaches that surface.

How does a light bulb work?

An electric current is passed through a filament

If white light is made up of all colors, how can you tell what color an object is?

An object reflects light of a certain color—which is the color that reaches your eyes—and absorbs all the other colors of light.

Why does a red ball look red?

Because it reflects red light waves and absorbs all others

Why does the light we see from stars take thousands of years to reach us?

Because the stars are very far away

Why is it necessary to have direct sunlight for this experiment?

Direct sunlight is a mix of all the colors and the rays of sunlight enter the water directly from the atmosphere without going through any other medium that might change them.

Based on the range of colors each can see, what difference can you infer between humans and dogs?

Dogs depend less on color cues

Sometimes when you are at a waterfall or a fountain you see a rainbow, even though there is no rain in sight. What is the BEST explanation for how that is possible?

Drops of water from the waterfall or fountain act as prisms, just like raindrops can.

Light is a form of what?

Energy. It is a kind of energy called electromagnetic energy.

Gamma rays have a higher frequency than visible light waves. What can you conclude from this?

Gamma rays carry more energy than visible light waves

A beam of light refracts when in travels from air into water. It refracts again—even more—when it passes from the water into glass. What can you conclude from this sequence of events?

Glass is denser than water.

When you see a bright green cell phone, you know that all the colors are being absorbed except which one?

Green

Light refracts when:

It changes speed

What does light do?

It fills our world and enables us to see what is around us.

What can you infer about the environment the anglerfish lives in?

It must be extremely dark

Why is it necessary to use mirrors to direct light around a corner or an obstruction?

Light only travels in a straight line, so mirrors are used to angle light in the proper direction. It doesn't curve around corners or obstructions.

What rules does light follow?

Light travels in a straight line and when a light beam travels from one medium into another medium, it bends, or refracts.

Why does refraction occur?

Light travels through different materials at different speeds

How is mixing the primary pigment colors together different from mixing the primary colors of light together?

Mixing the primary pigment colors gives you black; mixing the primary colors of light gives you white light

What are other types of electromagnetic energy?

Other types of electromagnetic energy include radio waves, ultraviolet (UV) waves, and x-rays.

What are the main colors in the visible light spectrum?

Red, Orange, Yellow, Green, Blue, Indigo, Violet

What is the difference between refraction and reflection?

Refraction is the "bending" of light waves as they travel from one medium into another medium. Reflection is when light rays bounce off of a smooth, shiny surface such as a mirror.

What is refraction?

Refraction of light occurs when light moves into another medium.

What does the term luminous mean?

Term used to describe things that give off their own light.

The rule is that "the angle of incidence is equal to the angle of reflection." What does that mean?

The angle at which light strikes a mirror is the same angle the beam makes when it reflects off the mirror.

Why does white light from the sun form a colorful rainbow when it passes through water droplets in the atmosphere?

The colors that make up white light refract at different angles

What is the difference between the crest of a wave and a trough of a wave?

The crest is the top, or highest point of a wave, while the trough is the bottom, or lowest point, of a wave.

How is wavelength measured?

The length of a light's wave or the wavelength is the distance between two nearest peaks (the highest places) or two nearest troughs (the place where it dips the lowest).

Why does a rainbow form on the paper?

The light is refracted as it passes from the air into the water. The mirror reflects the refracted light back through the water into the air, and as it passes into the air, the light is refracted further, so a rainbow becomes clear on the paper.

Where does most of the light we see come from?

The sun

What is color?

The wavelengths of light that are refracted or reflected. Color is in the light your eyes are detecting, not in the object you are looking at. Color is the way your brain interprets the wavelengths of light coming towards you.

How are prisms and raindrops alike?

They are both [transparent objects that are] able to split light into colors.

What statement about two people observing a rainbow must be true?

They each see slightly different rainbows

In what ways are the different colors of visible light different from each other?

They have different wavelengths and frequencies.

What characteristics do opaque objects have?

Those objects do not let any light through. Opaque objects block all light. They produce shadows.

A light bulb is an artificial light source. True or False

True

What is white light?

White light is a mixture of many different colors of light

How is a rainbow similar to the horizon?

You can never reach either of them

Why are trees and books lluminated objects?

You can see them because they reflect the light shining on them.

Which kind of object lets some, but not all, of the light through?

a translucent object

Who is ROY G BIV?

a way to remember the colors of the spectrum

Blue light bends more than red light when it passes through glass. Thus, blue light has a greater:

angle of refraction

What type of stuff can be refracted?

anything that travels in waves

The different colors of the visible light spectrum coalesce to make white light. What is the best synonym for "coalesce?"

combine

What are the primary pigment colors?

cyan, magenta, and yellow

What produces color?

different wavelengths of light

How does light travel?

in waves

When you see a rainbow, where are you seeing the colors?

in your brain—It is your brain that interprets the signals triggered by the light rays.

When you look at your teacher's face, how can you see it?

light reflects off her face

An object's color depends on what?

on which colors it absorbs and which ones it reflects.

What are humans? transparent, translucent, or opaque

opaque

What are the primary colors of light?

red, green, and blue

What are the seven colors of visible light?

red, orange, yellow, green, blue, indigo, and violet

What is the term for what happens when light travels from one medium to another?

refraction

Rainbows are the result of what?

refraction, so are prisms

Only a minute portion of the electromagnetic spectrum can be seen with the human eye. In this context, what does "minute" mean?

small

What is the purpose of the mirror?

to reflect the sunlight back up through the water into the air to demonstrate the refraction of the rays into the colors

Other objects, such as wax paper or frosted glass, let some light through but scatter or block the rest. What are those objects?

translucent

Light passes through some materials without scattering. We call objects of this kind what?

transparent

Red light waves have a longer wavelength than violet light waves. What can you conclude from this?

violet light rays have a higher frequency

Light can behave as both a ______________ and a _____________________.

wave; particle

Light's color depends most on its what?

wavelength

In which situation are you most likely to see a full circle rainbow?

while skydiving