2.2 Visible Light and Color 7.6.e Students know that white light is a mixture of many wavelengths (colors) and that the retinal cells react differently to different wavelengths 7.6.f Students know light can be reflected, refracted, transmitted, and absorbed by matter.

Visible Light Light can be either ▫A primary source of light-emits its own lightOR ▫A secondary source of light- reflects light from a primary source Key concept: “When light strikes an object, the light can be reflected, transmitted, or absorbed.”

When Light Strikes an Object When light strikes an object, the light can be reflected, transmitted, or absorbed.

Transparent It transmits most of the light that strikes it When light hits it the particles absorb but then reemit until the light finally passes through to the other side If there are any imperfections, in the material, they can scatter the light- similar to how translucent material reacts Transparent Squid

Translucent Scatters light as it passes through You can usually see something behind it but the details are blurred Examples: wax paper and frosted glass Translucent Reed Frog

Opaque Reflects or absorbs all of the light Cannot see through it because light cannot pass through it Opaque Idocrase

The Color of Objects Key Concept: The color of an opaque object is the color of the light it reflects.

Combining Colors Primary Colors 3 colors that can combine to make any other color Secondary Colors Produced when 2 primary colors combine in equal amounts Red and Yellow combine Blue and Yellow combine Red and Blue combine

Combining Colors- Light Key Concept: When combined in equal amounts, the three primary colors of light produce white light. Primary colors of light: red, green, and blue Secondary colors of light: when 2 colors combine in equal amounts Complementary colors- any 2 colors that combined and create white light If you combine a primary color and secondary color of light you get white

Combining Colors- Pigments The primary colors of pigments combine in equal amounts to form black. Primary colors of pigment are magenta, cyan, and yellow Pigments- colored substance that are used to color other materials Pigments absorb some light and reflect others Key concept- As pigments are added together, fewer colors of light are reflected and more and more are absorbed. If you combine any 2 primary pigments you get a secondary color- red, green, and blue