If you need to make ≈1.0M solutions of the metallic salts follow these instructions: Read a Safety Alert from the American Chemical Society about the traditional procedure for this demonstration.The American Chemical Society Committee on Chemical Safety recommends that this method be discontinued immediately. The traditional Rainbow Demonstration required that a highly flammable solvent, such as methanol or ethanol, be mixed with the metallic salts. This procedure is an updated version of the traditional one.The purpose is to demonstrate to students the variety of colors produced when different metals or metallic salts meet a flame. The Rainbow Demonstration (or Rainbow Flame Demonstration) is an activity popularly conducted in chemistry classrooms.Wash hands after handling materials used to prepare for or perform this experiment.Do not reach over it, tie back hair, and secure loose clothing. Keep flames away from flammable substances. Always use caution around open flames.Wear proper personal protective equipment when preparing and working with solutions.Safety goggles and lab apron are required. Students should wear proper safety gear during chemistry demonstrations.250 mL beaker or plastic or cardboard cup half full of waterĬopies of the visible light spectrum chart showing wavelength and frequency values.50 mL of 1.0M Strontium Chloride (SrCl 2).50 mL of 1.0M Calcium Chloride (CaCl 2).50 mL of 1.0M Barium Chloride (BaCl 2) - Note: Barium chloride is highly toxic.Wooden splints (number depends upon how many times the demo will be performed).Teacher Preparation: 30 minutes, longer if solution preparation is necessary This lesson supports students’ understanding of Identify an unknown metal by the color it emits when passed through a flame.Calculate the wavelength of light given its frequency.Calculate the frequency of light given its wavelength.Use flame tests to identify a metal or metallic salt by the color that it produces when it is put into a flame.HS-PS4-3: Evaluate the claims, evidence, and reasoning behind the idea that electromagnetic radiation can be described either by a wave model or a particle model, and that for some situations one model is more useful than the other.īy the end of this demonstration, students should be able to.HS-PS4-1: Use mathematical representations to describe a simple model for waves that includes how the amplitude of a wave is related to the energy in a wave.This activity will help prepare your students to meet the performance expectations in the following standards: In this demonstration, students will observe the variety of colors produced when different metals or metallic salts are heated in a flame.
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