The energy of colored light increases in order: red, yellow, green, blue, violet. What are the metallic elements used in the flame test in increasing order of energy of the light emitted?
Red: Strontium (dark), Lithium (crimson), Rubidium (red-violet)
Orange: Calcium (orange-red)
Yellow: Sodium (slightly orange)
Blue: Copper (blue-green), Cesium (blue-violet), Arsenic
Violet: Potassium (more pinkish, lilac)
There are plenty others, but here are some common ones. Correct me if I'm wrong in places.