Changes Caused by Light

• Describe the basic properties of waves, including wavelength, amplitude, and frequency.

• Explain that light is a wave that carries energy and can be reflected or absorbed.

• Use a model to describe how light's interaction with materials causes heating.

• Relate a light wave's amplitude and frequency to the energy it transfers.

Key Vocabulary

Wave

A repeating pattern that moves energy from one place to another without transferring any matter.

Wavelength

The distance between two identical points on a wave, like from one peak to the next.

Amplitude

The maximum height or depth of a wave from its rest position, which indicates its energy.

Frequency

The number of complete waves that pass by a specific point in a given amount of time.

Transmit

To allow energy, such as light, to pass through a material from one side to the other.

Reflect

To bounce energy, like light or sound, off of the surface of an object or material.

Key Vocabulary

Absorb

To take in energy from light and convert it into another form, like heat.

Light Source

An object or entity that produces and emits its own special kind of light energy.

Emit

To release or send out energy from a source in the form of waves or particles.

What Are the Properties of a Wave?

• Wavelength is the distance between two consecutive peaks of a wave.

• Amplitude is the maximum height of a wave from its central resting position.

• Frequency is the number of waves that pass a point per second.

Light: A Wave Carrying Energy

• Light is an electromagnetic wave that can travel through the vacuum of space.

• A light wave's amplitude determines its brightness; higher amplitude means more energy.

• A light wave's frequency determines its perceived color, like red or violet.

• Higher frequency light carries more energy than lower frequency light.

How Light Interacts with Objects

• Reflection is when light bounces off an object, like a mirror.

• Absorption is when light is taken in by an object, creating heat.

• Transmission is when light passes through an object, like glass or water.

• The wave model explains light as energy traveling in waves.

• Unlike sound, light can travel through the vacuum of space.

• Light is reflected, absorbed, or transmitted when it hits a material.

• The absorption of light energy can cause materials to heat up.