|ground state or ground level|
|Compare excited the lowest energy state of an atom, molecule, particle, etc|
|ground level or ground level|
ground state n.
The state of least possible energy in a physical system, as of atoms or molecules.
The state of a physical system having the lowest possible potential energy. For example, an electron in the lowest energy orbital in a hydrogen atom is in a ground state. The ground state of a physical system tends to be stable unless energy is applied to it from the outside; states that are not the ground state have a tendency to revert to the ground state, giving off energy in the process. Compare excited state.