Question

Among the solids, the higher melting point is exhibited by:
(a) Covalent solid
(b) Ionic solid
(c) Pseudo solid
(d) Molecular solid

Answer 1

Hint: The temperature at which the solid material changes into its liquid state is called a melting point. At the melting point, both states exist in equilibrium.

Complete Step by Step Solution:
Solid materials can be classified into two categories i.e., crystalline, and amorphous solid.
The crystalline material can further subdivide into ionic solid, molecular solid, covalent network solids, and metallic solids respectively.
Covalent Solid
Covalent solids are also known as network solids. In these solids, the covalent bond exists between the atoms.
The covalent solid has localized pair of bonding electrons between two atoms and as a result, the atoms have definite geometry.
Because in covalent solid the atoms are bonded in a continuous network, as a result, they have an extremely high melting point. The best example of covalent solids is diamond and silicon dioxide.
Ionic Solid
In an ionic solid the oppositely charges ions (cations and anions) are bound together by means of a strong electrostatic force of attraction. These ionic solids have a higher melting point than metallic solids and lower than covalent compounds. The melting point of ionic solid lies in the range of \[{300^ \circ }C\]to \[{1000^ \circ }C\]
Pseudo solid
Pseudo solid is also called amorphous solid or non-crystalline solid. They are not recognized as truly solid. They have a short range or arrangement of the constituent particle (atom ions and molecules). They can melt at low temperatures.
Molecular solids
In molecular solids, the molecules are bonded with each other by means of very weak intermolecular force. Therefore, this kind of solid has very lower melting points.

Therefore, the above statements indicate that the covalent solid has the highest melting point of the rest solids. Option (a) will be the correct answer.

Note: Glass, rubber, and plastic are belonging to non-crystalline or amorphous solids.