What is the smallest possible value of the principal quantum number n for an f electron?

The principal quantum number, n, may have a whole number starting by 1.

The possible numbers for n are 1, 2, 3, 4, 5, 6, 7.

The second quantum number, called Azimuthal, may be s, p, d or f. It identifies the kind of orbital in which the electron is.

Azimuthal and n numbers are related in this way.

If n = 1, Azimuthal can only be s

If n = 2, Azimuthal can only be s or p

If n = 2, Azimuthal can only be s, p or d

If n = 4, 5, 6 or 7, Azimuthal can be s, p, d or f.

Then, the smallest possible value of the principal quantum number for an electron f is 4.