Question

The valency of sulphide and oxide ions is:
a. -2
b. -3
c. -4
d. -5

Answer 1

Hint: We must be aware that the valency is the measure of an element’s power to combine with other atoms during chemical compound or molecule formation.

Complete answer:
Following our hint, valency is the range of electrons that a compound can lose, gain or even share. There are two basic fundamental understandings involved:
- We should understand the fact that Valence electrons are available in the outermost orbit of the atom.
- The maximum valency for an element could be four, which signifies four valence electrons in the outermost orbit at the most. Although, it might be very much possible that there are more than four valence electrons in the atom. In such cases, the valency is denoted by (8-n) for condition n>4, where n denotes the number of valence electrons.
- Well, the situation is a bit different for radicals. For radicals, the valency is equal to the magnitude of charge they carry.
- Now as we know that oxide and sulphides are radicals. They are denoted as $S{{O}_{4}}^{-2}$ (Suphide) and ${{O}^{-2}}$(Oxide).
- Hence for sulphide, we know sulphur can form 6 bonds and oxygen can form 2 bonds, hence through simple calculation we get the carried charge as +8 + (-2)*4 = -2.

Similarly for Oxide it would be -2.

Note: We know that the electrons are stored in various nucleus shells. But the outermost electrons are the one that combine with other elements to gain stability. This combination seeking behaviour has three types of configuration:
- Stable Configuration: Noble elements such as Helium
- Electron seeking Configuration: Chlorine, etc
- Electron losing Configuration: Sodium, etc