Mindy and her lab partner conducted flame tests of several metallic salt solutions. They dipped a wire loop into each salt solution, and one by one, heated the sample in the Bunsen burner flame. Based on their results, which element produced a colored light with the lowest energy?

A) barium

B) calcium

C) copper

D) potassium

Flame tests of metals produce various colors. The colors produced by each of the choices are:

A. barium - pale green

B. calcium - yellow red

c. copper - green blue

d. potassium - lilac

Using the visible light spectrum, it can be determined that the metal with the lowest energy is B. calcium. This is because the color yellow-red is near the end of the spectrum with the longest wavelength. Since wavelength is inversely proportional to energy, calcium has the lowest energy.