What is the flame test for potassium ions?

The flame test for potassium ions is characterized by a lilac color when the sample is heated. This distinctive color arises due to the specific wavelengths of light emitted as the electrons in the potassium atoms transition between energy levels. When potassium ions are introduced to a flame, the heat energy gives the electrons sufficient energy to jump to higher energy levels. As they return to their original states, they release energy in the form of visible light, which is observed as a lilac flame.

In contrast, other metals produce different flame colors. For instance, sodium ions produce a bright yellow flame, and calcium typically results in an orange-red flame. These differences in flame color are useful for identifying specific metal ions in a sample through simple observation.