1. Sixth Grade Science Unit ©j.slater 2011 Adapted from K.Reed

2. Why is light important to us? Can you think of 3 reasons? Light Energy LIGHT Light is needed for these reasons: We need light for sight Light produces heat Light provides us food through photosynthesis Sight heat photosynthesis

3. Light Producers vs. Light Reflectors Producers  Sun  Flashlight  Light bulb  Stars  Fireflies  Glo-sticks Reflectors  Moon  Mirror  Solar panels

4. LIGHT Big Ideas  Light travels 186,000 miles per second through air and space.  Light can be bent through reflection. Although light bounces back from every object it touches, some items reflect so much light (and absorb so little) that we can see our image on them.  Smooth surfaces are generally better materials for reflection than uneven surfaces.

5. LIGHT Producer vs Reflector  Light is a form of energy that you can see.  Light is one kind of radiant energy  Some items produce light, other reflect light. Producer or Reflector? (Underline the correct answer) Candle Mirror Sun Flashlight Jupiter REFLECTOR PRODUCER REFLECTOR & PRODUCER REFLECTOR STAND = Reflector SIT = Producer

6. How LIGHT Moves  Light travels in a straight line  Can you think of some real-life examples? flashlightlamp sun

7. How light Moves Label the following illustration: Be sure to use all the listed terms. mirror Angle of incidence Angle of reflection 45° Light Beam Mirror 45° Angle of incidence Angle of reflection Light beam

8. Refraction of Light  Light changes direction when it enters a new medium.  Medium: Any substance through which a wave is transmitted.  Example: Light in air, when it enters water it changes direction.  Light in air travels fast.  Light in water/glass travels more slowly  When light changes direction or bends it is called refraction  Refraction is caused by the change of the speed of light as it travels through different mediums.

9. Light  Remember: light is one kind of radiant energy.  Radiant Energy includes waves of all different wavelengths and frequencies.  When all the types of radiant energy are arranged in order, we have the electromagnetic spectrum.

10. Light  We can only see on part of the electromagnetic spectrum. That portion is called visible light.  What color is light from most lightbulbs? WHITE  Although we see white light, it is actually made up of many colors.  The colors of the visible light spectrum are: An easy way to remember these colors in order is: ROY G. BIV RED, ORANGE, YELLOW, GREEN, BLUE, INDIGO, VIOLET

11. Prisms  Prisms can be used to separate light into the colors of the spectrum.  The special lenses of the glasses were prisms. Now let’s look at a real prism and see how it separates light.  As a class, we’ll use a flashlight and prism to see how we can separate white light into the colors of the spectrum.

12. Prisms  Is using a prism the only way to see a rainbow?  When do you usually see a rainbow?  Can you explain why? We can see a rainbow after rain- the water in the air acts as a prism & separates the light.

13. Light & Color  If light is made of all the colors in the rainbow, how do we see certain colors? Why do we see white, red, or black? WhiteGreenBlack

14. Light & Color Why we see colors:  white: all colors strike, all colors are reflected.  red: all colors strike, red reflected (rest absorbed)  black: all colors strike, none reflected (all absorbed) YOU TRY IT!

15. Color & Light Vocabulary Light can be REFLECTED Light can be ABSORBED Light can be REFRACTED Light can be SEPERATED REVIEW: Using your notes. Complete the Light Vocabulary page at the beginning of your packet. bounced off trapped bent prism/rainbow

16. Transparent, Translucent, Opaque  Light that passes through matter is transmitted by the material.  If light is not transmitted, some of it is reflected.  If light is not transmitted or reflected it is absorbed. There are three types of material: Transparent Translucent: Opaque

17. Definitions  Transparent: Light passes through without being scattered.  Translucent: Allows some light to pass through (it is scattered).  Opaque: does not transmit light.