Question

is the correct way to write the abbreviated electron configuration for br?

Explanation:

Step1: Determine the atomic number of Br

Bromine (Br) has an atomic number of 35. Argon (Ar) has an atomic number of 18. So, we need to account for \(35 - 18=17\) more electrons.

Step2: Fill the orbitals according to the Aufbau principle

After \([Ar]\), the next orbitals are \(4s\), \(3d\), and \(4p\). The \(4s\) orbital can hold 2 electrons, the \(3d\) orbital can hold 10 electrons, and the \(4p\) orbital. Since \(2 + 10+5 = 17\), the configuration is \([Ar]3d^{10}4s^{2}4p^{5}\). The order of filling is \(4s\) before \(3d\) (Aufbau principle: lower - energy orbitals fill first. The \(4s\) orbital has lower energy than the \(3d\) orbital for filling purposes).

Answer:

\([Ar]3d^{10}4s^{2}4p^{5}\)