Question

Excited lithium atoms emit light strongly at a wavelength of 671 nm. This emission predominates when lithium atoms are excited in a flame. Predict the color of the flame

Short answer

The color of the flame is red.

Step-by-step solution

Chemistry on colors

The color of compounds is a physical property of these chemical compounds. It is due to the excitation of electrons by absorbing energy. This concept is explained by atomic spectroscopy.

Step 2: Prediction of the color of flame

Different colors have different wavelength ranges. For example, yellow has a wavelength range of $570-590\text{\hspace{0.17em}nm}$, orange color has a wavelength range of $590-620\text{\hspace{0.17em}nm}$, red color has a wavelength range of $620-750\text{\hspace{0.17em}nm}$etc.

The given wavelength is 671 nm. So it lies in the range of red in the spectrum.