Statement (I): For a given shell with principal quantum number \( n \), the total number of orbitals is indeed \( n^2 \), as each subshell (s, p, d, f) has \( l \) values, and the number of orbitals per subshell is \( 2l + 1 \). Therefore, the total number of orbitals for a shell is \( n^2 \).
- Statement (II): For any subshell with angular momentum quantum number \( l \), the spatial orientations of the orbitals are given by values from \( -l \) to \( +l \) including zero, which is also true.
Thus, both statements are true.