What colors do the salts of metals like sodium, lithium, potassium, calcium, strontium, barium, and copper emit when burned in a flame? See the colors with this Flame Tests of Metals by Daniel Rosenberg of the Harvard Natural Sciences Lecture Demonstration team:
We can analyze the component colors by placing a 500 lines/cm diffraction film in front of the camera lens.
Notice that some elements are mostly monochromatic (sodium, for example) while others emit a range of colors (calcium, etc). A slightly more quantitative analysis would incorporate a slit between the flame and the diffraction grating to make the profiles of the emissions narrower and more precise.
Related reading: Emission spectrum
Watch more from Harvard and more fire in chemistry:
• What’s the chemistry and physics of a flame?
• The Science Of Firework Color
• How is black fire made?
• Don’t extinguish a metal fire with water
• Candle Chemistry