An atom whose electrons have the lowest possible energies is called an atom in its ground state.

Here's why:

* Ground State: The ground state is the lowest energy state that an atom can occupy.

* Excited State: When an atom absorbs energy (e.g., from light), its electrons can jump to higher energy levels. This is called an excited state.

* Stability: Atoms in their ground state are the most stable because they have the lowest potential energy.

Let me know if you'd like to know more about energy levels in atoms!