# What is the ground-state electron configuration of a neutral atom of iodine?

Well, for iodine...$Z = 53$...
The number of protons, is EQUAL to the number of electrons in the NEUTRAL atom...and so we follow the usual $\text{Aufbau scheme..}$
${\underbrace{1 {s}^{2} 2 {s}^{2} 2 {p}^{6} 3 {s}^{2} 3 {p}^{6} 4 {s}^{2} 3 {d}^{10} 4 {p}^{6} 5 {s}^{2} 4 {d}^{10} 5 {p}^{5}}}_{\text{53 electrons as required...}}$