In Bohr’s model, the lowest energy level is called the ground state. The principal quantum number "n" equals 1 for this state. A. The ground state is unstable. The electron eventually spirals into the nucleus, just like in the solar system model. B. The ground state is stable. If no photons are directed at the atom, the electron will just stay in the n=1 orbit. C. The ground state is stable. However, the electron occasionally moves closer to the nucleus, but it quickly returns to n=1