What is ground level and excited level in physics?

In physics, ground level refers to the lowest energy state of an atom or molecule, where the electrons are in their lowest possible energy levels. Excited level, on the other hand, refers to higher energy states of an atom or molecule, where the electrons have absorbed energy and moved to higher energy levels. When an electron moves from the ground level to an excited level, it is said to be in an excited state. Excited states are temporary and unstable, and the electron will eventually return to the ground level by releasing the absorbed energy in the form of light or heat.

Ground Level:

- The lowest energy state of an atom, ion, or molecule.
- In this state, the electrons in the system occupy the lowest possible energy levels.
- The ground level is typically very stable and does not undergo any energy transitions readily.

Excited Level:

- Any energy state of an atom, ion, or molecule that is higher than the ground level.
- In this state, the electrons in the system have absorbed some energy and are occupying higher energy levels.
- Excited levels are unstable and typically have a short lifetime, eventually decaying back to the ground level through the emission of energy in the form of photons or other particles.