For \(n=3, \ell=1, m_\ell=0\): all three quantum numbers are fixed. This uniquely specifies one orbital — the \(3p_z\) orbital (or whichever p-orbital corresponds to \(m=0\)). A specific orbital is defined by its set of \(n\), \(\ell\), and \(m\). Only the spin quantum number \(m_s\) remains free.