1. 18.1: Light
Key concepts: What happens to the light that strikes an object? What determines the color of an opaque, transparent, or translucent object? How is mixing pigments different from mixing colors of light?
Key terms: transparent material, translucent material, opaque material, primary colors, secondary colors, complementary colors, pigment

2. Light
When light hits an object, the light can be reflected, transmitted, or absorbed.
Transparent materials – transmits most of the light that strikes it and light passes through without being scattered.
Translucent materials – scatters light as it passes through
Opaque materials – reflects or absorbs all of the light that strikes it. You cannot see through them because light can’t pass through.

3. The color of opaque objects
The color of an opaque object is the color of light it reflects.
A red apple looks red because it absorbs the other colors of the light spectrum (OYGBIV)

4. The color of transparent and translucent objects
The color of a transparent or translucent object is the color of light it transmits.
For example, when white light shines through a transparent blue glass, the glass appears blue because it transmits blue light.
Transparent and translucent materials are used to make color filters, like sunglasses.

5. Combining colors
Three colors that can combine to make any other color are called primary colors – red, green, blue. When combined, they make white light.
Two primary colors combining in equal amounts can produce a secondary color.

6. Mixing colors
A primary and a secondary color can combine to make white light.
Any two colors that combine to form white light are called complementary colors.
Yellow and blue
Cyan and red
Magenta and green

7. Mixing pigments Pigments are inks, paints, and dyes
Pigments absorb some colors and reflect others
Mixing pigments is different than mixing light!!
As pigments are added together, fewer colors of light are reflected and more are absorbed.
Cyan, yellow, and magenta are the primary colors of pigments. They combine to create black.

8. Bill Nye - light