Zn by itself doesn't have a primary quantum number 👎. a set of quantum number is particular to one electron of an element. An electron in 4s shell will have a 4 primary number and an electron in the 3d shell will have a 3 primary number. Zn will also have core electrons with primary quantum numbers 1 and 2 as well as 3 for the 3s and 3p subshells that will need to be filled before the 4s and 3d subshells can be filled.