Question

Element X has an electron configuration of 2-8-3. This element will combine with the phosphate ion to form a compound with the formula

Answer 1

X element can give 3 electrons, and ions X³⁺ can be formed.
Phosphate ion - (PO4)³⁻,
So compound will have formula  X³⁺(PO4)³⁻,
XPO4

Answer 2

Answer:

$XPO4$

Explanation:

First off, what is the chemical formula of the phosphate ion?

The formula of a phosphate ion is given as; (PO4)3−

The phosphate ion is a polyatomic ion with the empirical formula (PO4)3−

and a molar mass of 94.97 g/mol. It consists of one central phosphorus atom surrounded by four oxygen atoms in a tetrahedral arrangement. The phosphate ion carries a −3 formal charge.

With a formal charge of -3, it means the ion would have to gain 3 electrons when entering into a bond in order for it to be neutral.

X on the other hand as an electronic configuration of 2-8-3. The electron configuration reveals X has a valency (Number of electrons in the outermost electron shell) of 3. As such, X is a group 3 element (Aluminium to be much precise).

With valency of 3 it means X is willing and able to lose its 3 electrons to enter into a bond.

This leads to the formular between X and the phosphate ion to be $X^{3}(PO4)^{-3}$. XPO4

The formal charges balances each other (3 - 3 = 0). This means the total number of electrons lost by X is the total number of electrons received by the phosphate ion.