What is represented by the line absorption spectrum?

The line absorption spectrum is characterized by dark lines that indicate specific wavelengths of light that have been absorbed by a material, such as a gas. When white light passes through a cool gas, the gas absorbs certain wavelengths corresponding to the energy differences between electronic states of its atoms. This results in a spectrum where the continuous spectrum of light is interrupted by dark lines at specific wavelengths where the absorption has occurred. Each of these dark lines corresponds to a particular spectral line associated with an atomic transition, allowing us to identify elements present in the gas.

In this context, the other options do not accurately describe the nature of a line absorption spectrum. A spectrum with bright lines corresponds to emitted light, which is known as a line emission spectrum. A continuous light spectrum displays a seamless range of colors without dark lines. A spectrum consisting only of ultraviolet rays would not provide a complete picture of absorption characteristics across other wavelengths, thereby failing to capture the essence of the absorption spectrum.