* Energy Levels: Electrons occupy specific energy levels around the nucleus. These levels are quantized, meaning they can only exist at certain discrete energies.
* Excited State: When an electron absorbs energy (from light, heat, etc.), it jumps to a higher energy level. This is called an excited state.
* Distance from Nucleus: Higher energy levels correspond to orbitals that are located further away from the nucleus.
Think of it like this:
Imagine the energy levels like steps on a staircase. The lower steps are closer to the ground (nucleus), and the higher steps are further away. When an electron gains energy, it's like it climbs the staircase, moving to a higher step (energy level) further away from the nucleus.
Important Note: The movement of electrons is not a simple, continuous outward motion. Electrons exist in orbitals, which are regions of probability where they are most likely to be found. These orbitals have specific shapes and energies.
