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Identifying Elements
Task with Student Directions
Contributed by: Council of Chief State School Officers (CCSSO)

Welcome to this experimental science test. We hope that you will find it interesting and worthwhile. Carefully read through these directions and the directions on the next page before you begin to work.

You may be part of a group for the first part of this exercise. Each group should carry out the experiment and collect the data together, but each student must record the data in his or her own booklet. Be sure to record the data exactly as you observe them. After the data have been collected, each student should answer the questions independently.

After you have finished your experiment and have recorded all of the data, you will be asked to answer some questions about the experiment and the data you recorded. Your answers must be written in this test booklet in the space provided. Make sure that you understand each question before you begin to write. At any time while you are writing your answers, you may look back at the directions for the experiment and the data you collected. Be sure that your answers are written as clearly and neatly as possible.

Before you turn the page, read the list of materials given below and check to make sure that your group has everything listed.

Materials for Identifying Elements:
  • 1 pair of diffraction glasses
  • 1 set of colored pencils or markers
    (red, orange, yellow, blue, green, violet)
  • 1 bottle sodium solution
  • 1 bottle calcium solution
  • 1 bottle potassium solution
  • 1 bottle barium solution
  • 1 bottle copper solution
  • 1 bottle unknown solution
  • 6 nichrome wire loops
  • Bunsen burner
  • matches or striker
  • fluorescent light source
  • incandescent light source
  • pen or pencil

Identifying Elements

What are stars? What is their composition? If stars are so far away that it would take many lifetimes to reach one, how can we gather samples and collect data? How have astronomers managed to learn all that is known about stars?

In this event, you will use diffraction glasses to collect information. The procedure that you will follow is called spectroscopy. You will look at the spectrum produced by light bulbs. In addition, you will look at the colors produced when different chemical solutions are heated in a flame. Your observations and data will help you learn more about stars and about how scientists study them.

1. While wearing your diffraction glasses, observe a fluorescent light and an incandescent light bulb in your classroom. If possible turn off the other lights in the room.

2. On the Data Sheet, use the colored pencils or markers to color in the colors that you observe through the glasses. Color the blank in the approximate locations where you see each color when looking through the glasses. Each student should fill in the Data Sheet in his or her own booklet.

3. Follow safety protocol as directed by your teacher for the remainder of the work.

4. For the next part of this activity, you will use your nichrome wire loop and your set of small bottles. First, light your Bunsen burner, then put on your diffraction glasses.

Each bottle contains a different solution. Dip the nichrome wire loop in the solution and then place the loop in the flame. Observe the color of the flame as the solution is heated.

Record your information on the Data Sheet. Use the colored pencils or markers to fill in the color you observed.

5. Repeat this procedure for each bottle of solution. Be sure to record your observations on the Data Sheet. Also, be very careful when handling the solutions. Avoid getting them on yourself or other students.

6. Clean up the laboratory area as directed by your teacher. Wash your hands when you are finished with this event.

Data Sheet

For each spectrum band below, color the areas of the band to show what you observe when looking through the spectroscope.

Fluorescent Light Spectrum

Incandescent Light Spectrum

Sodium Solution Color

Barium Solution Color

Calcium Solution Color

Potassium Solution Color

Copper Solution Color

Unknown Solution Color


Please answer the following questions by yourself.

1. In what ways is the spectrum of the fluorescent light similar to and different from that of the incandescent light?

2. Compare the colors of the unknown solution to the colors of each of the other solutions. Based on your comparison, what is the composition of the unknown solution? Explain your answer by citing observations from your experiment.

3. Suppose the labels were missing from the bottles that you used for this event. Describe how you could use your colored drawings to identify which solution was in each bottle.


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