In Investigation Three, students will continue their study of light and optics. In PreLab, students will play a game to promote consolidation of the basic concepts of the transmission, absorbance, reflection, and refraction of light.

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1. Begin the Investigation by reviewing the concepts from Investigations One and Two. Use the activities from Investigation One, below, to briefly review absorption, transmission and reflection. Ask for student volunteers or simply refer to the slide as a means of review.

• Demonstration of the absorption of light.
• Demonstration of the transmission of light.
• Demonstration of the reflection of light.

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B. Inform students that light can interact with objects in one more additional way, refraction.

1. Ask students to read the definition of refraction in their Scientist’s Glossary.

Refraction: When light passes through a transparent object and is bent or redirected in a different direction.

2. Explain that when light travels through a transparent object its path through the object is bent, so that it exits the object in a different direction.

a. Place the masking tape on the floor to create a square approximately one by one meter. The tape should be placed on the floor in a visible part of the classroom.

b. Instruct a student volunteer to stand several meters away from the square outlined in tape on the floor.

c. Ask the student volunteer to enter the square from one side and then exit from one of the sides of the square on either side of the side that they entered.

d. Inform students that light entered the object with a certain path but its path was bent by the object, so it exited from the object on a different path.

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C. Inform students that to further review the absorption, transmission, reflection and refraction of light, the class will now play the Optics Game. Divide the class into pairs.

1. Ask students to remove the Optics Game Sheet and the Optics Answer Sheet from their Student Data Record and place them on the table in front of them.

2. Hand out one marker per pair of students.

3. Inform students that they will move their marker around the Optics Game Sheet in response to questions that you will ask them. Each student will record their answers on the Answer Sheet which will be checked for correctness by the other student in the pair.

4. There will be 1 point and 2 point questions. Students will move their markers 1 square for a correct answer to a 1 point question and 2 squares for a correct answer to a 2 point question.

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5. Refer to the shapes on the slide to help instruct the students in how to move their markers.

a. Markers that land on a Transmit square enter and then exit in the same direction according to the arrows.

b. Markers that land on a Refract square enter and then exit at 90 degrees according to the arrows.

c. Markers that land on a Reflect square enter and then exit at 45 degrees according to the arrows.

d. Markers that land on an Absorb square enter and cannot exit, effectively ending the game for that student.

6. The object of the game is to be the last person in the class with a marker that is not stuck in an Absorb square.

7. Instruct students to start the game by placing their markers on one of the Transmit squares in the corners of the Optics Game Sheet.

8. Use the 1 and 2 point questions below or make up your own:

• Which will absorb the most light, a dark shade or a light shade. Dark shade. 1
• Which will reflect more light a light shade or a dark shade. Light shade. 1
• What is the name of the instrument used to measure the degree of an angle? Protractor. 1
• Is a windowpane opaque or transparent? Transparent. 1
• T or F: When light strikes an opaque object it always bounces directly and straight back. F 1
• What do we call the angle at which light strikes a surface? The angle of incidence. 1
• What is light? Light is a form of energy that is visible to the human eye and allows us to see things around us. 2
• T/F: Only liquids can absorb light. F 1
• Which object would reflect more light, a piece of sandpaper or a piece of glass? A piece of glass. 1
• Which of the following is NOT a natural light: the Sun, a fire, a laser, a firefly? Laser. 1
• The Sun and the Moon. Which emits light and which reflects light? The Sun emits light, the Moon reflects light. 2
• How did we show that light contains heat energy? By shining it on a dark piece of paper. 2
• Can a transparent object reflect light? Yes, seeing yourself when looking out a window at night. 2
• What is a word that means the opposite of opaque? Transparent. 1
• What do we call the angle at which light bounces off a surface? The angle of reflection. 1
• Which do you think would get hotter if you shined a bright light on it, a white sheet of paper or a black sheet of paper? A black piece of paper. 1
• Name something in the room that is transparent. 1
• Name something in the room that is opaque. 1
• Which transmits more light, a light liquid or a dark liquid? A light liquid. 1
• Which liquid will absorb more light, a dark liquid or a light liquid? A dark liquid. 1
• If light strikes a reflective surface at 22 degrees, what will be the angle of reflection? 22 degrees 1
• Why was the black paper warmer than the white paper after being exposed to the lamp? Dark shades/colors absorb more energy. Light colors/shades reflect light energy. 2
• What is the Law of Conservation of Energy? Energy cannot be created or destroyed, but it can change forms. 2

9. Continue the game for at least two rounds to allow both students from each pair to play one round. Instruct students to record answers on the back of their Optics Game Sheet.

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D. Inform students that in the Lab, they will use their knowledge of reflection to solve a problem. In doing so, students will explore these questions:

Can light be reflected more than once?

Do the Laws of Reflection apply when light is reflected several times?