What is the absorption spectrum of an element?

The absorption spectrum of an element is indeed a spectrum of light absorbed by that element. When light passes through a gas or vapor of an element, specific wavelengths of light are absorbed due to the energy transitions of electrons within the atoms of the element. Each element has a unique set of energy levels, and when photons of specific energies (or wavelengths) interact with these atoms, they absorb only those photons that match the energy difference between the lower and higher energy levels of their electrons.

As a result, the absorption spectrum appears as a series of dark lines or bands superimposed on a continuous spectrum of light, indicating the wavelengths of light that have been absorbed by the element. This unique pattern allows scientists to identify the presence of specific elements in a sample, making absorption spectra a powerful tool in analytical chemistry and astrophysics.

The other options do not accurately describe the absorption spectrum. A chart of atomic radii does not relate to light absorption, while a representation of ionization energies focuses on how much energy is needed to remove an electron rather than the absorption of light. A spectrum representing emitted light relates to emission spectra, which depicts the light emitted by electrons dropping to lower energy levels, rather than light absorbed by an element.