The Flame Test is a safer version of the traditional Rainbow Demonstration, an exercise popularly conducted in chemistry classrooms. The purpose of The Flame Test is to demonstrate to students the variety of colors produced when different metals or salts meet a flame. It contributes to their understanding of:
- Energy
- Electromagnetic Spectrum
- Atomic structure
- Atomic spectra
- Electrons
- Visible light spectrum
The Flame Test
Developed by the American Association of Chemistry Teachers (AACT)
By the end of this demonstration, students should be able to:
- Use flame tests to identify a metal or metallic salt by the color that it produces when it is put into a flame.
- Calculate the frequency of light given its wavelength.
- Calculate the wavelength of light given its frequency.
- Identify an unknown metal by the color it emits when passed through a flame.
Companion Resources for the Flame Test
- Playing with Fire: Chemical Safety Expertise Required (Journal of Chemical Education - free access through 2018)
- Safety Data Sheets: Information That Could Save Your Life (ChemMatters)
- Teacher's Guide [DOCX] (ChemMatters)
- Key Lessons for Preventing Incidents from Flammable Chemicals in Educational Demonstrations (Chemical Safety Board)
More about the Traditional Rainbow Demonstration
Notice: ACS's Committee on Chemical Safety recommends that the “Rainbow” demonstration on open benches involving the use of flammable solvents such as methanol be discontinued immediately due to extreme risk of flash fires and flame jetting.
- Safety Alert: The Rainbow Demonstration [PDF] (ACS, Committee on Chemical Safety)
- How To Make Chemistry Classroom Demonstrations And Experiments Safer (C&EN)
Warning
Exercise extreme caution around large containers of flammable liquids in the presence of an ignition source. Flame jetting can occur, causing flames to shoot out 15 feet or more.
