AIIMS 2019 Chemistry Flame Test MCQ Question

Lithium (Li) produces a crimson red flame due to the excitation of its electrons, which emit light at a wavelength of approximately 670 nm, corresponding to the red region of the visible spectrum. This flame color indicates that lithium has a relatively high wavelength compared to other metals. Sodium (Na) indeed gives a golden yellow flame, but it does not have the maximum wavelength among the options; potassium (K) produces a lilac or violet flame, and cesium (Cs) emits a blue flame, both of which are at shorter wavelengths than lithium's crimson red. Thus, while all options describe flame colors accurately, only option A correctly identifies lithium's flame color and its relative wavelength.