Question

What is the electronic configuration for As?

Answer 1

Arsenic is the element from group 15. It has the atomic number of 33. Arsenic is the element of the p-block. Aufbau proposed the filling of electrons.the filling of electrons takes place in s, p, d, and f orbitals, according to various energy levels.

Complete answer: Electronic configuration of any element tells us the total number of electrons in that atom or the atomic number of that element. Electronic configuration of any element consists of filling the orbital with electrons. The filling of electrons in various orbitals is according to a principle of Aufbau. The filling takes place in s, p, d, and f subshells. These subshells are written along with the number of shells, like 1,2, or 3.
Now, we have been given the element Arsenic, As, with an atomic number of 33. It has 33 electrons, so according to Aufbau, filling will take place as:
As =$1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}3{{p}^{6}}3{{d}^{10}}4{{s}^{2}}4{{p}^{3}}$ , this is the electronic configuration of As.
It can also be written by writing a noble gas (argon) and then writing the remaining electrons as,
As = [Ar]$3{{d}^{10}}4{{s}^{2}}4{{p}^{3}}$ , argon with 18 electrons is added and remaining electrons are written as it is.
The diagrammatic representation of the Aufbau diagram is as follows:

The arrows denote the order of the filling of electrons. s can accommodate 2 electrons, p can have 6, d can have 10, while f can have 14 electrons filled.
Hence, the electronic configuration of arsenic, As is written as $1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}3{{p}^{6}}3{{d}^{10}}4{{s}^{2}}4{{p}^{3}}$ or [Ar]$3{{d}^{10}}4{{s}^{2}}4{{p}^{3}}$.

Note: Another way to show the electronic configuration is writing it without sub shells (s, p, d, f). It is written showing the electrons in shells of K, L, M, N, that can have 2, 8, 18, 32 electrons respectively. So As will have configuration of As= 2, 8, 18, 5.