All the alkali metals and their salts (particularly chlorides due to their more volatile nature ) impart a characteristic color to the oxidizing flame of Bunsen burner. Which of the following imparts yellow color in a flame test?

Options

A. Li
B. K
C. Na
D. Cs

Answer

C

Explanation

To perform the flame test, a sample of the metal chloride or any salt of the metal moistened with conc. HCI is heated on a Pt or nichrome wire in a Bunsen burner flame. The heat from the burner excites one of the orbital electrons to a higher level. When the excited `e^(-)` drops back to its original energy level, it gives out the extra energy it obtained. For alkali metals, the energy emitted appears as visible light thus, giving the characteristic flame colorations.