Question

An element Z forms an oxide $Z{{O}_{3}}.$ What is the valency of this element and what will be the formula for fluoride of Z?

Answer 1

We know that the maximum number of univalent atoms originally hydrogen or chlorine atoms that may combine with an atom of the element under consideration, or with a fragment, or with a fragment, or for which an atom of this element can be substituted.

Complete answer:
As we know that the valency is a parameter to measure the ability of an atom or element to form a molecule or compound. It can also be defined as the number of bonds the element can form in a compound. Valency, unlike oxidation number, has no sign. The number of electrons released or gained by an element while forming a chemical bond is termed as its valency.
The compound given above is a metal oxide and we have to find its atomic number, valency and to find these we will also evaluate its electronic configuration. The ionic compounds are formed by the combination of positively charged cations and negatively charged anions. The ionic compound formed must be neutral so the positive and negative charges are balanced. Oxide ion is a ion with two charge, and as the formula of oxide is $Z{{O}_{3}},$ the valency of the ions must be six which when represented in simple whole number ratio is $1:3.$ The fluoride is a ion with one charge and as valency of the element is $+6.$ Thus the formula of its neutral fluoride is $Z{{F}_{6}}.$

Note:
Remember that the Valency is the number of electrons required to complete its octet. Whereas, oxidation number is the charge of an element, either independently, or in a compound. Valency of fluorine is $1,$ whereas oxidation number of fluorine is $-1.$