What do quantum numbers specify about electrons?

Quantum numbers provide a detailed description of the properties of electrons within an atom, particularly their energy levels and spatial distribution around the nucleus. The four quantum numbers — principal (n), angular momentum (l), magnetic (m_l), and spin (m_s) — collectively reveal information about an electron's energy, the type of orbital it occupies, the orientation of that orbital, and the electron’s intrinsic spin.

The principal quantum number indicates the main energy level of the electron, which also implicitly suggests how far the electron is likely to be from the nucleus. The angular momentum quantum number describes the shape of the orbital (s, p, d, f), while the magnetic quantum number specifies the orientation of these orbitals in space. Finally, the spin quantum number tells us about the two possible orientations of an electron's spin within an orbital.

This comprehensive set of information conveyed by the quantum numbers is crucial to understanding an atom's electronic structure and behavior in chemical bonding. Thus, the answer that reflects this accurate description of electrons is the one that mentions their energy and place in orbitals.