text: who can explain to me what orbitals and sub-orbitals are? also, what are the connections between them and principle energy levels and quantum numbers? i am so confused. i don't know what a suborbital is, but an orbital is the region where an electron spends 90 percent of its time. in other words, it's the region where the electron has a .9 probability of being there. this is based on psi squared from the schrodinger equation.  at each energy level, there exists orbitals. these orbitals are defined by a set of quantum numbers: n, l, ml, me