Which flame color indicates the presence of potassium ions?

Which flame color indicates the presence of potassium ions?

• A. Blue
• B. Lilac
• C. Red
• D. Orange

Answer: (B)

In a flame test, metal ions are identified by the color of the flame produced when they are heated, because the excited electrons emit light at characteristic wavelengths. Potassium atoms release light mainly in the purple–violet part of the spectrum, giving a pale lilac flame. This distinctive lilac color is the telltale sign of potassium ions in a sample. Other flame colors, like blue, red, or orange, are associated with different elements and do not indicate potassium.

In a flame test, metal ions are identified by the color of the flame produced when they are heated, because the excited electrons emit light at characteristic wavelengths. Potassium atoms release light mainly in the purple–violet part of the spectrum, giving a pale lilac flame. This distinctive lilac color is the telltale sign of potassium ions in a sample. Other flame colors, like blue, red, or orange, are associated with different elements and do not indicate potassium.