Quantum numbers are simply the idea of our electrons. So if we have a unique electron in a given atom, that electron has four unique quantum numbers that are unique to that electron. So we have the principal quantum number, we have the Zimmerfo quantum number, and we have two more quantum numbers. Now, the principal quantum number gives the energy level of that electron. The second quantum number, known as the Zimmerfa quantum number gives or designates the shape of the orbital, and it's represented by the letter L, and it could be 00:12 and so on, zero being the S shape, one being the P shape, two being the D shape. The third quantum number specifies exactly which orbital that our electron is in.