Here's why:
* Energy Levels: Electrons in atoms occupy specific energy levels. Higher energy levels are further away from the nucleus.
* Energy Transitions: When an electron moves from one energy level to another, it either absorbs or emits energy. The amount of energy involved depends on the difference between the two levels.
* Adjacent Levels: Transitions between adjacent levels (e.g., from n=2 to n=3 or from n=4 to n=5) involve smaller energy differences compared to transitions between more distant levels (e.g., from n=2 to n=5).
Therefore, transitions between adjacent energy levels require the least amount of energy.
