Question

Configuration of $B{r^ - }$is : $[Ar]3{d^{10}}4{s^2}4{p^6}$ The electronic configuration of $B{r^ + }$ would be identical with the element:
A.Se
B.As
C.Ga
D.Ge

Answer 1

Electronic configurations are a representation of where the electrons are present around a nucleus. Nucleus is the centre of an atom and it contains positive protons and neutral neutrons bound together. A neutral atom is known to hold equal number of protons in a nucleus and number of negative electrons surrounding the nucleus. There electrons are present in the orbits surrounding the nucleus

Complete step-by-step answer: These electrons in an atom are to be placed into an arrangement and this arrangement will help us indicate their energy and shape of the orbital in which they are present.
The electronic configuration for $B{r^ - }$ is :$[Ar]3{d^{10}}4{s^2}4{p^6}$. Here $B{r^ - }$ is an anion. In its neutral state, it has $7$ electrons in its outer shell and as we need 8 electrons in its outer shell to meet the noble gas configuration, it forms $B{r^ - }$ anion
The electronic configuration for $B{r^ + }$ is: $[Ar]3{d^{10}}4{s^2}4{p^3}\;$. This configuration is identical to that of element Arsenic. Here the ion is cation as the bromine atom here has lost an electron.

Hence the correct option is B.

Note: When we talk about the atom’s orbitals, we must know the types of orbitals and how many electrons each can contain. Also, we need to know that we need two electrons to fill an $s$ orbital, six electrons to fill an$p$ orbital, ten electrons to fill a $d$ orbital and fourteen electrons to fill the $f$ orbital. These electrons are filled in an order. This order is based on their energy’s order. The terms given to this filling of electrons is called the Aufbau principle. This principle states that “The lowest energy orbitals will fill first”.