Question

In which set do all elements tend to form cations in binary ionic compounds?

In which set do all elements tend to form cations in binary ionic compounds?

S, F, Br

N, As, Bi

Ca, Zn, Sn

Li, Sn, O

I need to know why?

Answer 1

In the given options, Ca, Zn and Sn tend to form cations in binary ionic form. The reason lies in their electronic configuration.

Electronic configuration for these 3 elements is given as:

Ca: [Ar]4s² ; Zn: [Ar]3d¹⁰4s² ; Sn: [Kr]4d¹⁰5s²5p²

Molecular compounds are electrically neutral and metals tend to loose their valance electrons(electrons in outter most shell) to form cation hence participate in bond formation.

As the mentioned elements have two valence electrons (4 in Sn) they tend to form binary cations.

As Sn has 4 electrons in the outer most shell it is stable in 2 cationic forms Sn⁺² & Sn⁺⁴ thus Sn also tends to form binary ionic compounds.

Ca and Zn have 2 electrons in their outer most shell leading to the formation of Ca⁺² and Zn⁺² . Binary cations formation finally leads to binary ionic molecules