Question

Which of the following formulas represent valid ionic compounds that can be made from these six elements: Al, Be, F, Li, N, and S? Select all that apply. A. AlN B. BeS C. AlLi D. LiF

Answer 1

Answer:

A. AlN B. BeS D. LiF

Explanation:

Ionic bonding:-

This type of bonding is formed when there is a complete transfer of electrons from one element to another element. In this bonding one element is always a metal and another is a non-metal.

Thus, Al, Be, Li are metals and F, N, S are non metals which can form ionic bonding with each other. So, AlLi (Option C) rules out.

Considering the option A: - AlN

Aluminium has a valency of 3 and nitrogen of 3. To find the ionic compound, the valency of the cations and the anions are interchanged and are written in subscripts. Thus,  

                           Al         N

                            3          3

Simplest ratio : -  1            1

The ionic compound formed is :- (a) AlN and thus it is a valid ionic compound.

Beryllium has a valency of 2 and sulfur of 2. To find the ionic compound, the valency of the cations and the anions are interchanged and are written in subscripts. Thus,  

                           Be         S

                            2          2

Simplest ratio : -  1            1

The ionic compound formed is :- (b) BeS and thus it is a valid ionic compound.

Lithium has a valency of 1 and fluorine of 1. To find the ionic compound, the valency of the cations and the anions are interchanged and are written in subscripts. Thus,  

                          Li           F

                           1            1

The ionic compound formed is :- (d) LiF and thus it is a valid ionic compound.