1 class periods of 45 minutes each
Students use diffraction glasses to explore the colors found in the
visible spectrum of light. They mix the primary colors using color paddles and
liquids to make orange, green, and purple. Finally, students observe the 'dots'
used to make colored pictures in magazines.
- Rainbow/diffraction glasses -- Carolina Biological 755225 $9.50 for 6
- lamp -- any desk lamp will do
- color paddles -- Carolina Biological 956028 $10.25 for 3 sets of 6
- magnifying lenses
- colored magazine pictures
- test tubes or any small clear cup
- food coloring -- red, blue and yellow
- 100 ml beakers or small bowls
- plastic pipettes or medicine droppers
- picture of a rainbow
Background for Teachers
Visible light separates into the spectrum red, orange, yellow, green, blue,
indigo and violet. These colors can be memorized in order using the saying 'Roy
G. Biv'. Diffraction or rainbow glasses separate visible light. Water droplets in the
air can also separate visible light creating rainbows.
Red, yellow and blue are the primary colors. The secondary colors are red
and yellow to make orange, yellow and blue to make green, and blue and red to
make purple. Colored magazine pictures are made using separately colored dots
placed very closely next to each other. When looking at pictures with our eyes
alone, we see one solid color but when pictures are looked at with magnifying
lenses the individual dots of colors can be distinguished.
Intended Learning Outcomes
- Framing questions. Conducting investigations. Collecting data.
- Sharing ideas with peers. Connecting ideas with reasons.
Pre-lab discussion:Ask students about the 5 senses and explain that today
they are studying their sense of sight. Show students the rainbow picture and
recite the color names in order. Show students a picture from a magazine and
then using the baby picture of the dots explain how magazine pictures are
formed. Use the color paddles to demonstrate the primary colors and the mixed
- Diffraction glasses: Look through the diffraction glasses. Study the colors
of the rainbow seen. Recite the color names in order: red, orange, yellow,
green, blue, indigo and violet. Notice that the colors always occur in this order.
Have students look out the window, up at the ceiling lights and at a lamp with
the glasses on to see the bright effect.
- Color paddles: Have students try mixing the secondary colors of orange,
green and purple with the color paddles. Students can then each take a paddle
and take turns mixing their color with the color paddle of the other students in
their group. When they have seen the combinations they can make, let them
look at different objects in the room through the paddles.
- Magnifying lenses: Have the students use a magnifying lens to look at
colored pictures in a magazine. Notice how it seems like one color to our eyes
without lenses; however, with magnifying lenses they see all the dots that are
used in printing colored pictures.
- Make a rainbow: In 100 ml beakers or small bowls, prepare the solutions
of the three primary colors using food coloring. Make the solutions fairly dark for
the best results. Have each student make the color orange, green and purple by
putting in one pipette full of the primary color needed into test tubes. After the
three main color combinations are made, allow the students to experiment with
different amounts of the colors to see what new colors they can make.
Rio Tinto Hands-on Science Curriculum Team
- Ms. Rae Louie -- Administrator, Principal Beacon Heights Elementary
- Emily Mortensen -- Grant writer, teacher outreach, 2nd grade teacher at Beacon Heights Elementary
- Ruth Li -- Curriculum design, K-6 Science Educator at Indian Hills Elementary
- Deirdre Straight -- Curriculum development, K-6 Science Educator at Beacon Heights Elementary
- Tim Rausch -- Website development, Library Media at Beacon Heights Elementary