Science Study Guide Light, Chapter 9 Fourth Grade Vocabulary Definition Absorb To take in Lens An object that refracts light Example Light A from of energy that travels in waves and can be seen when it interacts with matter Opaque Not allowing light to pass through Prism A transparent object that separates white light into all the colors of the rainbow
Vocabulary Definition Reflect To bounce off Example Refract To bend from a straight path, as a light ray through a lens Shadow An area where light does not strike the ground Translucent Allows only some light to pass through Transparent Lets, allows, light through
Lesson One What Is Light? Light is a form of energy that travels through space. Examples of light: sun, fires, fireflies, and electric light bulbs. Light is energy Light travels in waves Light waves travels in a straight line, in all directions. Light waves travel away from their source. Light waves can travel through certain kinds of matter, such as air or clear glass. Light waves can travel thorough empty space. The boy sees the objects when light waves bounce from their surfaces to his eyes Light and Matter Light reacts in different ways when it meets different kinds of matter Opaque An opaque material blocks light from passing through it. Transparent A transparent material allows light to pass through it. Translucent A translucent material allows some light to pass through it. Shadow An area where light does not strike. The shadow is the shape of the outline of the object that is blocking the light. Sharp Shadows The nearer an object is to the shadow it casts, the sharper the shadow edges and the shadow is similar to the size of the object. Blurry Shadows The farther the object is from the shadow it casts, the larger the shadow and the blurrier its edges.
Lesson Two How Is Light Reflected? Light waves reflect or bounce off the surfaces of most objects. Light waves travel in straight lines. How light waves behave when they strike an object depends on the object s surface. When you look at a mirror, the light waves reflect off its smooth, shiny service. The light waves bounce back to your eyes. You see yourself. Objects that are not smooth and shiny, the light waves strike them and the light waves bounce back in many directions. You see the object. Refract To bend light when is passes through air, water, and glass Lens A piece of curved glass, plastic, or other material that refracts light. Lenses can enlarge or refine and image. Examples of lenses are: Magnifying Glass, Microscope, Eyeglasses, telescope. The Eye The sense organs that help people see. Eye has many parts to help people see. The lens is located behind the cornea and pupil. The lenses in your eye refract light to form images (upside down) on your retinas. Your brain interprets those images and turns them upright for you to understand.
Lesson Three What Is Color? Sunlight A collection of light waves of different colors. Also called white light. Prism A piece of glass or other transparent material that separates white light into colors. A triangle piece of glass can act as a prism. Tiny droplets of water that hang in the air can act as a prism. This is called a rainbow. The colored bands from a prism are always arranged in the same order: red, orange, yellow green, blue, indigo, violet. See Colors Most objects will absorb or take in, some of the light that strikes their surface. A colored object absorbs some colors of light but reflects other colors. You see only the reflected colors. Objects that absorb nearly all the light that strikes them appear black. Objects that that reflect nearly all the colors that strikes them appear white. Colored Light The color of an object depends upon the color of light it reflects. It also depends on the color of the light shining on it. White objects appear to change color under colored light.