1. Source of the project

The phenomenon of color is very common in daily life, and we are also very interested. Therefore, we use science and technology activity classes for study and research. Some interesting experiments have been added to this series of activities, and most of them are our own experimental instruments and scientific works, which really let us use our brains freely.

Second: experimental objectives

1, common sense understands that white light is composed of colored light.

2. The color of transparent body is determined by the colored light passing through it, while the color of transparent body is determined by the colored light it reflects.

3, the effect of color and light mixing, three primary colors.

4. Mixing effect of pigments.

Third, the implementation process.

This series of activities is divided into four parts, about six extracurricular activities.

Part I: Dispersion of light (1, 2 is one class hour, 3 and 4 are two classes hours).

1 .white light decomposition. (group experiment)

Let a beam of sunlight shine on the white screen through the prism (as shown in figure 1), observe the white screen and record the experimental results.

2. Color light synthesis. (Group experiment with self-made experimental instruments)

The light decomposed by sunlight is mixed into white light by prism. Don't be too far away from the second prism, so as not to lose too much light energy and the brightness is too weak. And make a box about 40 cm long, and try to fix the two prisms in proper positions A and B. (Figure 2) Open a slit at C to let sunlight in.

3. Spray Chen Hong experiment. (Self-made experimental instrument)

Rainbow is formed by the reflection and refraction of sunlight in the air into water droplets. Countless small water droplets are equivalent to small prisms. Sunlight hits the water droplets, and after two refractions and one reflection, it will disperse. (as shown in figure 3)

Take a glass tube with a pointed tip, connect it with a rubber hose, turn on the faucet and form a parabolic fountain in the air. There are countless small drops of water around the fountain. We can turn our backs on the sun and observe the beautiful artificial rainbow. This is the spray Chen Hong experiment.

4. Ring rainbow experiment. (Self-made experimental instrument)

Take a colorless transparent thin-walled spherical flask with a diameter of about 8 cm, fill it with clear water and fix it. Then take a three-splint, drill a small hole with a diameter of about 4 cm in the middle, put it into a spherical flask with a diameter of about several centimeters, aim the round hole at the bottle, and paste white paper on the side close to the bottle. Sunlight enters the flask through a small hole, and after reflection, it falls on a circular rainbow on white paper. (as shown in figure 4)

The first part needs to be equipped with: 1, prism; 2, prism, cardboard; 3. Pointed glass tube and rubber tube; 4, spherical flask, plywood, white paper, mirror.

The second part: the color of the object

1, the color of the object. (group experiment)

Find some papers with different colors: white, black, red, green and blue, and then find some transparent cellophane with the same color as above and a flashlight with strong light ratio. Put some colored paper on the wall. In a dark room, first illuminate each piece of paper with white light from a flashlight and write down their colors. Then cover the front end of the flashlight with each transparent colored paper, and illuminate each colored paper in turn with different colors of light to record the observation phenomenon.

Conclusion:

The second part is the experimental equipment: colored paper, colored transparent paper and flashlight.

The third part: the mixture of color and light.

1, color gyro. (Students make their own experimental instruments)

Make a color gyro (as shown in Figure 5), make three hard paper plates and paint them with three colors (or paste them with three colors of paper). Cut a groove along the radius, insert three discs alternately along the notch, and cover them on the gyro to expose three fan-shaped areas of red, green and blue. Toggle the disks respectively, adjust the area of three sectors, change the proportion of three colors, try again and again, see a variety of colors, and record the results.

2. Striped gyro. (Students make their own experimental instruments)

The production of striped gyro (as shown in Figure 6). Half of the cardboard disc is painted black, and the other half is divided into four equal parts to draw black stripes, so that the gyro can rotate at high speed for a long time, and the excellent light can be seen and the results can be recorded.

The third part of experimental equipment: high-quality gyro, cardboard tray, pigment or colored paper.

Part IV: Pigment mixing

1, pigment mixing experiment. (group experiment)

Ask the students to say specific colors with pigments and record the results. Draw a watercolor painting for the competition with the adjusted color. The selection criterion is that the color meets the requirements, and the content of the painting is rich in connotation, creative and healthy.

The fourth part is experimental equipment: pigments and drawing paper.

Four: Harvest experience

The "Color Mystery" series of scientific and technological activities is rich in content, and the experiments are novel and interesting. We can study independently and happily in a free atmosphere, give full play to the spirit of innovation, develop scientific potential, cultivate practical skills, deepen scientific concepts and improve scientific quality.