Question

Sulphur molecule is converted into Sulphur ion, when it:
(A) Gains two electrons
(B) Loses two electrons
(C) Gains two protons
(D) Shares two electrons

Answer 1

Hint: Sulphur molecule is a neutral molecule. Sulphur ions are charged. When we consider how the molecule gets converted into ions, we will be able to understand whether Sulphur has gained, lost or shared two electrons or gained two protons.

Complete answer:
Sulphur is a chemical element with atomic number $16.$ It is represented with the symbol ”S” in its elemental form. In molecular form, it exists as a ${S_8}$ molecule. It is a non-metal, belonging to group $16$ and period $3$ of the periodic table. It is multivalent, meaning it has many valencies that it can exist in. Sulphur in its ionic form exists as ${S^{2 - }},$ because it accepts two electrons to form Sulphide ions.
The electronic configuration of neutral Sulphur atom is:
\[S(16):{\text{ }}1{s^2}{\text{ }}2{s^2}{\text{ }}2{p^6}{\text{ }}3{s^2}{\text{ }}3{p^4}\]
The electronic configuration of Sulphide ion is:
\[{S^{2 - }}(18):1{s^2}{\text{ }}2{s^2}{\text{ }}2{p^6}{\text{ }}3{s^2}{\text{ }}3{p^6}\]
Let us look at the conversion of Sulphur molecule to Sulphide anion:
$\dfrac{1}{8}{S_8} + 2{e^ - } \to {S^{2 - }}$
We can see in the reaction that the Sulphur molecule accepts two electrons to become Sulphur ions. Hence, the Sulphur molecule is converted into Sulphur ion, when it (A) gains two electrons.

Note:
Sulphur is an abundant element. The outermost shell of Sulphur has $6$ electrons. It exhibits variable valencies like \[ - 2, + 2, + 4, + 6\;.\] However, even though Sulphur is multivalent, it is most stable while existing as Sulphide ion ${S^{2 - }}$ as on gaining two electrons, it is able to complete its octet. In different compounds, it has different valencies.