Give the formulae of the chlorides of the elements A and B having atomic numbers of 6 and 11 respectively. Wil the properties of the two chlorides be similar or different? Explain.

Explanation

(i) The atomic number of element A is 6, so its electronic configuration is 2,4. Now, an atom of A has 4 electrons in its outermost shell and requires 4 more electrons to achieve the 8-electron configuration and become stable. Thus, the valency or element A will be 4. We know that the valency of chlorine is 1. So, one atom of element A will share its four electrons with 4 atoms of Cl to form a covalent compound having the formula `ACl_(4)`.
(ii). The atomic number of element B is 11, so its electronic configuration is 2,8,1. Now, an atom of B has only 1 electron in its outermost shell which it can give (to a Cl atom), and form a cation `B^(+)`. and by gaining 1 electron, the chlorine atom (Cl) forms an anion `Cl^(-)`. Now, the ions `B^(+)` and `Cl^(-)` combine to give an ionic compound having the formula BCl.