Name: Period: The Color Spectrum Lab Step 1: Make an observation Ions within the ionosphere react with ultraviolet radiation produce the aurora effect. C Step 2: Ask Questions 1. What characteristic colors will be produced by various metallic ions? 2. What test will we use to determine the metal ions? Step 3: Create a Hypothesis If energy in the form of a flame is used to test metallic ions, then________________________________ _____________________________________________________________________________________ Step 4: Conduct an Experiment 1. What safety precautions should we take? 2. What will our independent variable be? 3. What will our dependent variable be? 4. How will we clean the spatula to avoid contamination? Materials: 7 small test tubes filled (and label) with the following solutions: o 15ml Sodium chloride o 15ml Potassium chloride o 15ml Lithium chloride o 15ml Calcium chloride o 15ml Strontium chloride o 15ml Copper (II) chloride o 15ml Barium chloride 1 small beaker filled with 30mL of acid Expo marker- to label test tubes Bunsen Burner Rubber tubing Spatula Safety goggles Procedure: 1. 2. 3. 4. 5. 6. 7. 8. 9. Gather and check all materials and lab equipment. Place 7 test tubes in holder and on your lab bench away from flame. Dip spatula into one of the solutions, completely immersing the tip. Hot spatula over flame and observe the color change. Turn down the lights if needed. Record data. a. All flames will start out blue in color or invisible but will change to the colors characteristic of the metal salts. b. The copper chloride will begin to burn after a few minutes. Be sure thoroughly extinguish this fire with water. Dip the spatula into the acidic solution. Repeat steps 3-6 for the remaining 6 solutions. Clean up lab station, turn off burner and see Mrs. Dawson for discard instructions. Have lab station checked by TA or Mrs. DAwson Step 5: Record Data Chloride Solution Sodium chloride Potassium chloride Lithium chloride Color of Flame Calcium chloride Strontium chloride Copper (II) chloride Barium chloride Step 6: Conclusion: 1. How does this experiment relate to Earth Science? 2. When an element or compound is placed in a burning solution, the atoms absorb energy and promote electrons to “excited” energy levels, which are different from their normal ground state. Explain how this creates colored light. 3. What is the name of this spectrum of specific wavelengths produced by exciting an element? 4. Why is the spectrum different for every element?