Why does each element have its own set of characteristic absorption lines?

Question

Quizplus · Accepted Answer

Absorption lines are created when the electrons of an element absorb energy and move to a higher energy level. The specific energy levels and transitions available for each element are determined by the unique electron configurations, which result from the number of protons and electrons in the atom. Therefore, each element has its own set of characteristic absorption lines.

Why Does Each Element Have Its Own Set of Characteristic