In a flame test, which color is produced by copper?

In a flame test, which color is produced by copper?

• A. Crimson red
• B. Bright yellow
• C. Violet
• D. Blue-green

Answer: (D)

In a flame test, the observed color comes from light emitted by excited electrons as they return to lower energy levels. Copper ions release light predominantly in the blue-green part of the spectrum, so the flame appears blue-green. This distinct color helps identify copper in a sample. The other colors correspond to emissions from other elements (red from some alkaline earths, yellow from sodium, violet from potassium), so they don’t match copper’s characteristic emission.

In a flame test, the observed color comes from light emitted by excited electrons as they return to lower energy levels. Copper ions release light predominantly in the blue-green part of the spectrum, so the flame appears blue-green. This distinct color helps identify copper in a sample. The other colors correspond to emissions from other elements (red from some alkaline earths, yellow from sodium, violet from potassium), so they don’t match copper’s characteristic emission.