Question

The electronic configuration of chloride ion is:

(A) 2,8,7

(B) 2,8,6

(C) 2,8,8

(D) 2,8

Answer 1

Hint: Electronic Configuration is nothing but the arrangement of electrons in energy levels around an atomic nucleus in orbit. Generally electronic configuration is done to determine the group, periods, valency and valence electrons of the element.

Complete step by step answer:

Let us first know about chlorine.

Chlorine has atomic number 17. It has 7 outermost electrons and its valency is 1, so electronic configuration of chlorine according to Neil Bohr, there are four subshells in the nucleus ; they are particularly divided into K, L, M, N. So the electronic configuration of chlorine in k sub shell having 2 electrons need to be filled and in L sub shell 8 electrons to be filled and in M subshell there will be 7 electrons, then its general electronic configuration is $2,8,7$.

Now, we observe that chlorine is one electron less than achieving the stable electronic configuration of its nearest Noble gas, Argon. Therefore, Chlorine gains an electron (remember not from any empty space, either from metal or a semimetal) and chloride ion is formed, with electronic configuration of $2, 8, 8$.

Hence, the electronic configuration of chloride ions is $2, 8, 8$. Therefore, option (C) is the required answer.

Note: Electron configuration provides insight into the chemical behavior of elements by helping determine the valence electrons of an atom. It also helps classify elements into different groups. Thus making it easier to study the properties of the element.