Question

The electronic configuration of an element with an atomic number 12 is _________.

Answer 1

Hint: Atomic number of any element is the total number of electrons present in that atom, which is also equal to the total protons in that atom. The electronic configuration of any element consists of filling up the atomic orbital and shells according to the energy levels from lower to higher. This is in accordance with the Aufbau rule.

Complete answer:
Electronic configuration of any element tells us the total number of electrons in that atom which is also equal to the atomic number of that element. Electronic configuration of any element consists of filling the shell that has sub shells with electrons. The shells consist of various subshells from lower to higher energy level, there are 4 shells K, L, M, N. The filling of electrons in various subshells is according to a principle of Aufbau that takes place from the lower energy level to the higher energy level in the subshells s, p, d, f.
Element with atomic number 12 is Magnesium of group 2. According to filling of the shells K, L, M, N, the configuration will have K = 2, L = 8, M = 2. So, 3 shells will be filled as $1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}$.
 So, the electronic configuration of an element with an atomic number 12 is $1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}$.

Note:
The maximum number of electrons in shells K, L, M, N is 2, 8, 18, 32 respectively, while in subshells s, p, d, f there are orbitals that has 2 electrons, s has 1, p has 3, d has 5, f has 7 orbitals that can accommodate 2 electron each. The filling takes place in s, p, d, and f subshells. These subshells are written along with the number of shells, like 1,2, 3, etc.
The diagrammatic representation of the Aufbau diagram is as follows: