Light and Color

NGSS

• MS-PS4-2. Develop and use a model to describe that waves are reflected, absorbed, or transmitted through various materials.

Objectives

Content Objectives:• Participate in a gallery walk

to discuss properties of light and its behavior.

• Identify the three types of matter in which light interacts with.

Language Objectives:• Define transparent,

translucent, and opaque. • Identify the three types of

matter in which light interacts with using the following sentence frame:The three ways light interacts with matter are ____________________.

Types of Matter (this goes in your dictionary)

• Transparent: describes matter that allows light to pass through with little interference.

• Translucent: describes matter that transmits light but that does not transmit an image.

• Opaque: describes an object that is not transparent or translucent.

Light and Matter

• When light or waves strike any form of matter, it can interact with matter in three different ways—the light can be reflected, absorbed, or transmitted.

• Reflection happens when light bounces off an object.• Reflected light allows you to see things.• Absorption is the transfer of light energy to matter. • Absorbed light can make things feel warmer.• Transmission is the passing of light through matter.

Light and Matter

• You can see objects outside because light is transmitted through the glass.

• You can see the glass and your reflection because light is reflected off the glass.

• The glass feels warm when you touch it because some light is absorbed by the glass.

Checking for understanding

• What are the three ways in which light interacts with matter?

• Use the following sentence frame:The three ways light interacts with matter are

_________________________.

Types of Matter (this goes in your dictionary)

• Transparent: describes matter that allows light pass through with little interference.

• Translucent: describes matter that transmits light but that does not transmit an image.

• Opaque: describes an object that is not transparent or translucent.

Types of Matter

Checking for understanding

• What are the three types of matter?The three types of matter

are____________, ___________, and ____________.

• What is an example of a transparent object?

An example of a transparent object is ____________________.

Checking for understanding

• What is an example of a translucent object?

An example of a translucent object is _________________.

• What is an example of an opaque object?An example of an opaque object is

____________________.

Colors of Objects

• Humans see different wavelengths of light as different colors.

• The color that an object appears to be is determined by the wavelength of light that reach your eyes.

• Light reaches your eyes after being reflected off an object or after being transmitted through an object.

• http://phet.colorado.edu/en/simulation/color-vision

Colors of Opaque Objects

• When white light hits an opaque colored object, some colors are absorbed and some are reflected.

• Only the light that is reflected reaches your eyes.• The light that is reflected to your eyes determines

the color you see.• White object—all colors of light are reflected.• Black object—all colors are absorbed.

Colors of Translucent Objects

• Ordinary glass window is colorless in white light because it transmits all the colors that strike it.

• When you look through colored transparent or translucent objects, you see the color of the light that was transmitted through the material. The other colors were absorbed.

Colors of Translucent Objects

• This bottle is green because the plastic allows green light to pass through it. The rest of the colors were absorbed.

Mixing Colors of Light

• In order to get white light, you must combine all colors of light.

• You can also get white light by adding just three colors of light together—red, blue, and green.

• Red, blue, green are called primary colors of light.

Mixing Colors of Light

• Primary colors of light are red, blue, and green.

• Secondary colors of light are the result of two primary colors added together. Yellow, magenta, and cyan

Mixing Colors of Pigment

• Pigment: substance that gives another substance or a mixture its color.

• Mixing red, blue, and green paint won’t give you white paint.

• Paint contains pigment which makes it different from colors of light.

Pigments and Colors

• Almost everything contains pigments.• Chlorophyll and melanin are two examples of

pigments.• Chlorophyll gives plants a green color, and

melanin gives your skin its color.

Color Subtraction

• When you mix pigments together, more colors of light are absorbed or taken away.

• Mixing pigments is called color subtraction.• Primary pigments are yellow, cyan, and

magenta.

Exit Cards

• Tweet the Lesson: • @Name• Use one of the sentence starters to tweet

about the lesson• #LightandColor