Properties of Light Lab Instructions Grade 7 Science Westmount High School

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1 Name: Date: Properties of Light Lab Instructions Grade 7 Science Westmount High School Purpose: To learn about the properties of light. This session requires you to visit 12 different stations to discover the various properties of light. Start at a station that is available and move through each station one at a time. You will have a little less than 5 minutes per station. Station 1 Incandescence In front of you there are two identical incandescent light bulbs. Look carefully at the filament in each bulb. How do you think the light is created? Bring your hand near the lit bulb WITHOUT TOUCHING IT. Does this form of light produce heat? Unplug the light socket and observe the light bulb. Is the bulb still producing light? Station 2 Fluorescence In front of you there are two identical fluorescent light bulbs. What do you think is inside these bulbs? How is the light created? Bring your hand near the lit bulb WITHOUT TOUCHING IT. Does this form of light produce heat? Unplug the light socket and observe the light bulb. Is the bulb still producing light? Station 3 Phosphorescence Look at the various phosphorescent (glow-in-the-dark) objects in the darkness of the box. Do they produce light? If so, is the light produced dim or bright? Now, charge the various phosphorescent items using the UV light and then place them back in the darkness of the box. What colour is the light produced by the phosphorescent objects? Is the light dimmer or brighter than before? Shine the UV light onto the white piece of paper at your station. What is the secret message? Now you write a secret message (keep it positive!) on a new sheet of paper for the next group to discover. Station 4 Reflection Moonlight is created when the light from the sun bounces off the moon. Try to use your mirror to cast moonlight onto the hidden dark object at your station. Draw or name this dark object. Station 5 Refraction Place the pen in the beaker of water. What do you notice about how the pen looks in the beaker? Does the thickness of the pen appear different inside the water? Use the ray box and the semi-circular piece of Lucite to bend the light ray. Using the giant protractor on the table, measure the angles of the ray going in and coming out of the Lucite.

2 Station 6 Diffusion Using the ray box, shine a ray of light into the dish with plain water in it. Then shine a ray of light into the dish with milky water in it. Describe how the light ray behaves in the two types of water. Station 7 Dispersion Using a prism and the ray box, create a rainbow. Place the second prism in the path of the rainbow and adjust it until white light exits the second prism. Draw a quick sketch of your setup showing the ray box, the two prisms, the white light rays and the rainbow. Station 8 Absorption Warning: This station involves using lasers. These are very dangerous. DO NOT POINT THE LASER AT ANY ONE AT ANY TIME. Do not point the laser towards a window. Pass the light from the white pen light through each set of gummy bears and through the gummy worm. What colour is the light that comes out the other side of the gummy candy? Now, pass the light from the green laser pointer through each set of gummy bears and through the gummy worm rainbow. What colour is the light that comes out the other side of the gummy candy? Does the green light pass through all the colours of gummy candy? Which colours absorb the green laser completely? Which colours absorb the green laser partially? Now, pass the light from the red laser pointer through each set of gummy bears and through the gummy worm rainbow. What colour is the light that comes out the other side of the gummy candy? Does the red light pass through all the colours of gummy candy? Which colours absorb the red laser completely? Which colours absorb the red laser partially? Station 9 Types of Materials Using the screen and raybox, pass light through each of the objects at your station. Classify each object as transparent, opaque, or translucent. Station 10 Shadows Place one of the cardboard obstacles in the holder on the optical bench. The obstacle should be between the light source and the screen. Slide the obstacle so that it is close to the screen. Describe the shadow you see. Now, slowly slide the obstacle away from the screen (towards the light source). What do you notice about the shadow? Describe what you see. Station 11 Pinhole camera Find the pinhole in the pinhole camera and point it towards the light source. Look at the screen on the other side of the camera. Draw what you see. Is the image bigger or smaller than the light bulb? Is the image of the light source flipped horizontally? Is the image of the light source flipped vertically? Station 12 Coloured light In each section of the Venn diagram, write the name of the colour that is created when you combine the different coloured lights on the screen.

3 Name: Date: Properties of Light Lab Observation Sheet Grade 7 Science Westmount High School For each station, record your observations in the space provided. Station 1 Incandescence The light is created by. This form of light (produces/does not produce) heat. When the light socket is unplugged, the bulb light. Station 2 Fluorescence There is inside the fluorescent light bulb. The light is created by. This form of light (produces/does not produce) heat. When the light socket is unplugged, the bulb light. Station 3 Phosphorescence The phosphorescent objects (produce/do not produce) light. The light is (not visible/dim/bright). The charged objects produce a light. The light is (dimmer/brighter) than before. The secret message is. Station 4 Reflection Draw or name the hidden dark object. Station 5 Refraction The pen looks in the water. The thickness of the pen is in the water. The incoming angle is. The outgoing angle is.

4 Station 6 Diffusion In plain water, the ray. In milky water, the ray. Station 7 Dispersion Sketch of two prisms, the rainbow, the white light rays, and the ray box: Station 8 Absorption Red gummy bear Colour of light exiting the gummy candy White light Green light Red light Green gummy bear Orange gummy bear Yellow gummy bear White gummy bear Station 9 Types of Materials Transparent Opaque Translucent Station 10 Shadows When the obstacle is close to the screen, the shadow is. When the obstacle is far from the screen, the shadow is.

5 Station 11 Pinhole camera Pinhole camera screen drawing: The image is (bigger/smaller) than the light bulb. The image horizontally flipped. The image vertically flipped. Station 12 Coloured light Red light Blue light Green light