Question

Does anybody know the principle quantum number of an atom that has s, p, d, f orbitals?

I'm pretty sure the number is inbetween 2-4, but I am unsure of how to figure out the principle quantum number just using that information.

Thanks in advance!

Answer 1

Remember the azimuthal quantum number? s electrons have an azimuthal quantum number of 0, p electrons = 1, d electrons = 2 and f electrons = 3.
The azimuthal quantum number can run from 0 to N-1; therefore, for an f electron (azimuthal quantum number 3), N must be at least 4. You won't find elements in period 4 with f electrons but those orbitals are available at N = 4. Where do they fill? The Lanthanide series is the 4f series. The Actinide series is the 5f series.