Final answer:
A line emission spectrum for lithium consists of discrete wavelengths of light that are emitted when lithium atoms transition from excited states to lower energy states. Each element has a unique set of emission lines.
Step-by-step explanation:
A line emission spectrum for lithium consists of discrete wavelengths of light that are emitted when lithium atoms transition from excited states to lower energy states. When a sample of lithium is heated or subjected to an electrical discharge, the atoms become excited and emit light at specific wavelengths. The line emission spectrum for lithium would include lines at characteristic wavelengths determined by the energy levels of the atom.
This is similar to the line spectra observed for other elements, such as hydrogen, sodium, and iron. Each element has a unique set of emission lines, which are the result of electron transitions within the atom.