Question

Given that electron transfer between atoms is an unfavorable process, why do ionic solids such as MgCl2 exist?       (5)

Answer 1

Ionic bonding occurs because metal have few electrons in their outermost orbitals.By losing these electrons metals can achieve noble gas configuration, stability and satisfy octet rule.

Similarly, non metals have close to 8 electrons in their outermost orbitals so they tend to accept electrons to achieve noble gas configuration and satisfy octet rule.

The charges on the anion and cation corresponds to the no. of electrons donated or received. The net charge in an Ionic compound is zero.

In MgCl2. Mg donates two electrons to achieve stability(noble gas configuration ) and each Cl atom accepts 1 electrons to achieve noble gas configuration.