Question

What is the electronic configuration for ${S^2}$ ion?

Answer 1

Hint : As we know the general process of writing electronic configuration, first we will see atomic number of sulphur atoms and then we can know atomic number of sulphur ions. Then like any other electronic configuration we will start filling up the $spdf$shell blocks respectively as required.

Complete Step By Step Answer:
Sulphur belongs to group sixteen in periodic table and period three, it has atomic number $16$ which means it has sixteen electrons surrounding the nucleus.
We will first write electronic configuration of sulphur atom
$S:1{s^2}2{s^2}2{p^6}3{s^2}3{p^4}$
In sulphur ion two extra electrons will get added which will be put in $3p$ orbital which can hold maximum six electrons
So now to write sulphur ion
${S^{2 - }}:1{s^2}2{s^2}2{p^6}3{s^2}3{p^6}$ .

Note :
The sulphur atom and sulphur ion have same nuclear charge but sulphur ion has eight electrons in valence shell which experience greater amount of electron – electron repulsion than the sulphur atom which has six valence electrons and that is why sulphur ion has larger radius than sulphur atom and for same reason sulphur atom would be attracted into magnetic field.