Question

Electron drop to lower energy levels when they____(emit/absorb) energy.

Short answer

Electron drop to lower energy levels by emitting energy.

Step-by-step solution

Given information.

We have been given that,

Electron, energy levels from higher to lower.

We need to state whether electron emit or absorb energy when they drop to lower energy levels.

Simplify

Electron emit energy when they drop to lower energy levels.

Electron emit energy to lower its kinetic energy and gain stability. Electrons in higher energy levels don't stay for long ,they will eventually fall back to their original energy level (ground state) where they can remain stable.