 Fireworks are a very important part of human celebrations. The bright colors and patterns of the displays never cease to amaze and entertain across generations and societies. In this lesson, we will learn how to test for positive ions, using the idea of fireworks as our learning base. Let's say you are given six files of solids. You are told that they are ionic compounds and you have been asked to determine the identity of the cation or positive ion of each one. To do so, you would conduct a flame test. Clean nichrome wire in concentrated hydrochloric acid and place in a roaring Bunsen burner flame. Repeat until no color is produced, thereby confirming that the nichrome wire is thoroughly clean. Place the nichrome wire in concentrated hydrochloric acid again and scoop some of the unknown solid onto the loop. Place at the edge of the roaring flame and you will find that each sample produces a characteristic color. Ensure that the nichrome wire is adequately cleaned between each test or contamination will occur and the flame color produced may not be strong. Sodium ions produce a yellow-orange flame. Potassium ions produce a lilac flame. Calcium ions produce a brick-red flame. Strontium ions produce a red flame. Copper ions produce a blue flame. And barium ions produce a light green flame. Notice that with the exception of copper, all samples are either group 1 or group 2 metal ions. Why is concentrated hydrochloric acid used in a flame test? Please pause the lesson to think about this and resume when you are done. Concentrated hydrochloric acid is used because the resulting metal chloride formed is more easily vaporized, hence making the flame test easier to conduct. These flame colors arise due to the fact that electrons become excited when heated and jump to a higher energy level. When they fall back down to their original energy levels, they release the energy absorbed in the form of a wavelength of light. The wavelength of light released is unique and we see this as a certain color. This chemistry has made fireworks shows possible around the world. In conclusion, a flame test can be used to identify certain positive ions as they emit a characteristic flame color.