An element `E` has a valency of `4`.
(i) What will be the formula of its chloride ?
(ii) What will be the formula of its sulphide ?

Explanation

In order to solve this problem, we should know the valencis of chlorine and sulphur elements (because chlorine forms the choride and sulphur forms the sulphide). Knowing that the valency of chlorine is 1 and that of sulphur is 2, the abvoe problem can be solved as follows :
(i) Formula of chloride of element E

Thus, the formula of chloride of element E is `ECl_(4)`.
(ii) Formula of sulphide of element E

Thus, the formula of sulphide of element E is `ES_(2)`.
(It should be noted that the element E having a valency of 4 is like carbon, C. So, the chloride `ECl_(4)` is like carbon tetrachloride, `C Cl_(4)`, and the sulphide, `ES_(2)` is like carbon disulphide, `CS_(2)`).