The quantum numbers n=2, l=1, and ml=0 specify a 2p orbital, one of the three possible p orbitals in the second energy level.
The quantum numbers provided, n=2, l=1, ml=0, designate a certain type of orbital. The principal quantum number (n) determines the energy level of the electron, which in this case is the second energy level. The angular momentum quantum number (l) determines the shape of the orbital, and with a value of 1, this specifies a p orbital.
Lastly, the magnetic quantum number (ml) indicates the orientation of the orbital, and with a value of 0, it is one of the three possible p orbitals. Thus, the type of orbital designated by these quantum numbers is a 2p orbital, specifically one of the three 2p orbitals.