How do people and scientists make discoveries?
How do humans create colors?
A dye is a coloring matter that can or cannot be dissolved in a liquid.
Dyes can come from plants and plant parts.
Colors of the rainbow can be produced from objects that are in nature.
Evidence was collected to help students understand that dyes can come from plants
Exploring and Experimenting helps us to learn about nature and how to create tools and everyday objects to survive and enjoy life.
Science has been used for thousands of years and has changed the ways people
think about occurrences in nature. Science is an ongoing human endeavor. Many
people throughout history have made contributions to science through learning
about objects, events, and phenomena in nature. One of these contributions is
extracting plant dyes.
To gain knowledge of this process, students practice scientific methods as they carry out controlled and trail-and-error experiments. As a result of their dying experiments students will make connections with the History and Nature of Science.
Another follow-up experiment could be to add a small amount of alum and cream of tartar to the dye bath and see how it might affect the color.
Activity 1-Indoor Rainbow
Materials: Wide-mouthed, smooth, circular glass jar or large plain drinking glass filled with water, small mirror, flashlight, dark room with white walls
1. Ask students what causes a rainbow?
2. Give students all three objects and ask them how they can create a rainbow using all three objects-the glass, mirror and flashlight. Either allow the students to explore and try to figure it out on their own and give the following suggestions as needed or give the suggestions before letting them explore. Submerge part of the mirror or the entire mirror in the glass filled with water. Shine the flashlight on the mirror above the water, below the water, or above and below the water. Change the angle of the light from the flashlight or change the angle of the mirror. When all of the groups have been successful bring the class back together.
3. Have groups share their results and describe what they needed to do to get a rainbow of colors.
4. What is the best position for the mirror?
5. What is the best position for the flashlight?
6. Have the groups share their observation with other groups.
7. As the students where the colors came from.
8. Ask them if they think the colors are in the light.
9. Ask the students what causes a rainbow to form on the wall.
10. How does this experiment help you to understand something in nature?
11. How did you use evidence and reasoning to understand?
12. How is what you did compare to what scientists do?
13. How can you use what you learned today?
14. How do other people use what you learned today?
Activity 2-Milk Rainbow
Materials: 1 pie tin, milk, 3 different bottles of food coloring, 1 bottle of liquid soap
1. Ask students what will happen if they put drops of food coloring (drops are in the shape of a triangle) in a pie tin filled with milk at room temperature.
2. Listen to responses. Do not comment on accuracy.
3. Ask the students what will happen if they put a drop of liquid soap right in the middle of the triangle drops of food coloring.
4. Have the students do the activity.
5. Ask students to share their observations with the class and reach a conclusion about the observations.
6. Ask where the colors come from. Do they come from inside the milk? Water? Food coloring? Soap? How come they change? Is color light? Where does light come from? Could yesterdays activity give you an idea that might relate to this? Could the like all around you have something to do with the color? If so what?
7. What evidence and reasons do you have to support your answers?
8. How would a scientist answer these questions? How would a scientist explain what happens?
9. How does what you learned apply to other things?
10. Will this same reaction work with water or soda pop?
11. What happens if you put the soap on the outer edge of the milk in the pie tin?
12. How would a scientist answer these questions?
Activity 3-Rainbow in a Bag
Materials: 1 Ziploc baggie for each student or group, 1 large sauce pan, 16 cups of water, 4 cups of cornstarch, 1.5 cups of sugar, 1 large wooden spoon, food coloring (red, blue, yellow)
Prepare ahead of time a batch of goop known as rainbow stew. Bring the water to a boil in the pan, toss all ingredients except the food coloring, and heat until it thickens, stirring occasionally. Divide mixture into thirds.
You may want to add food coloring (one heaping teaspoon) to make one batch red, one yellow, and the last one blue or you may want to wait and have students add it later. The bags may be squeezed to mix the colors together.
1. Ask students how many colors can be made by combine the three primary colors of red, blue and yellow.
2. Wait for responses. Mark them on the board.
3. Give the students the rainbow bags.
4. Have students compare their observations
5. Have them take small amounts of the primary colors and mix them. Have them record the colors used and the color made. Samples may be preserved for later reference. A class chart could be made to look for patterns.
6. Bring the class together and ask the students to share their data.
7. Ask what patterns they can discover.
8. Ask them to explain how the colors are made. Where does the light come from that they see as each color?
9. How did the colors form?
10. Ask students if they can explain how to make different colors and how to make them get lighter or darker.
11. Ask how they were working as scientists.
12. Ask how they might use what they learned in this activity.
Activity 4-Colors from Plants
Materials: White construction paper, markers, onion skins, flower blossoms, cranberries, bark from woodpile, leaves, beets, red cabbage, tea, carrots, blue berries
1. Ask students what will happen if they rub the vegetables, flowers, leaves, etc. on the white paper.
2. Ask students what colors they think can be created from the plants provided.
3. Ask students why the colors of the plants appear on the white paper.
4. Have students fold white construction paper into six sections.
5. Ask students to create a rainbow of colors using the plants on their folded white paper.
6. Record all of the different colors on a class chart.
7. Have groups discuss the results.
8. Have groups compare their results with other groups and explain why this happens.
9. Ask how this information can be used in everyday life.
10. Ask how scientists use this information to create objects that we use today.
11. How would a scientist answer these questions?Activity 5-Exploring Plants-Plant Dyes
Materials: Hot water, beakers, stirring implements, various white fabrics, trays lined with paper towels, masking tape, onion skins, flower blossoms, cranberries, bark from woodpile, leaves, beets, red cabbage, tea, carrots, blueberries, safe tools for cutting, mortar and pestle for grinding, tweezers, hot mitts
1. Ask students what will happen to the water if ground-up plant parts are immersed into the water.
2. Ask students what will happen if white cloth is submerged into that water.
3. How and why does this happen?
4. Have students cut up plants, or grind tougher materials with the mortar and pestil.
5. Put it in a heat-resistant container, add hot water and stir or mash thoroughly.
6. Have the students add the white fabric and allow it to soak for about 5 minutes.
7. While the fabric is soaking, ask students what they think would happen if cold water was used. Would it work as well as hot water?
8. Remove the fabric with tweezers and set on a tray lined with paper towels. Allow drying overnight.
9. Ask how did the dyes form.
10. Explore with dyes by repeating these methods. Have students document on the towels their results.
11. Ask students what will happen if we re-dye the white fabric again.
12. Ask what dyes changed the fabric the most?
13. Why did this happen?
14. Encourage students to share their observations as they work.
15. Have the class discuss the results and journal these findings.
16. Ask students what might happen if we add another substance such as alum or cream of tartar.
17. Ask students to give justifications for their predictions.