The flame color observed for Li+ in a flame test is which color?

• A. Red
• B. Green
• C. Yellow
• D. Blue

Answer: (A)

In a flame test, heating an element excites its electrons, and when they drop back to lower energy levels they emit light at specific wavelengths. For lithium ions, this emission falls in the red part of the spectrum, so the flame appears bright crimson-red. This distinctive red helps identify lithium and distinguish it from other common ions: sodium gives yellow, potassium gives a lilac/purple, calcium gives brick-red/orange-red, and copper gives blue-green. So the observed flame color for Li+ is red because of the characteristic red emission from its excited electrons.