Question

Which one is the softest solid non-metal among the following?
A.Diamond
B.Oxygen
C.Sulphur
D.Bromine

Answer 1

Hint: The texture of a substance depends on the strength of the intermolecular bonding and the number of bonds formed by each atom. Bromine is present normally as a liquid or gaseous state. Diamond is the hardest occurring material.

Complete step by step answer:
Diamond is made up of carbon, in which each carbon atom is $s{p^3}$ hybridized and is arranged in a 3-dimensional tetrahedral arrangement of atoms. The strong covalent bonding of the carbon atoms makes diamond the hardest substance known.
Oxygen molecules are formed from two oxygen atoms joined to each other through a double bond. Solid oxygen is seen to form at normal atmospheric pressure at a temperature below $54.36{\text{K}}$ and it is a clear blue solid.
Sulphur is a yellow solid with the smell of rotten eggs. It is a brittle solid with poor electrical conductivity.
Bromine is a red coloured liquid at room temperature. At a pressure of 75 GPa, the orthorhombic crystals of bromine are formed while at 100 GPa pressure monoclinic crystals can be seen. As oxygen and bromine are not solids so being soft or hard is not applicable to them hence the softest solid non-metal from them is option C, sulphur.

Hence,option C is correct.

Note:
The property of the solids that indicate the materials resistance to abrasion and deformation is called hardness or softness of the solids. Various methods are used to characterize hardness among which the Mohs scale for hardness of metals is included and is based on the ability of a harder metal to scratch the surface of the softer one.