Solid State MCQs - Quiz

Ice is the only substance that has a lower density as a solid than as a liquid. Its density is 0.92 g/cm3 as a solid and 1 g/cm3 as a liquid. Mercury has a density of 14.184 g/cm3 as a solid and 13.69 g/cm3 as a liquid. Carbon dioxide has a density of 1.56 g/cm3 as a solid and 1.10 g/cm3 as a liquid. NaCl has a density of 2.71 g/cm3 as a solid and 1.556 g/cm3 in molten state.

Crystalline solids are homogeneous in composition, meaning that the composition of the solid is uniform throughout. Additionally, crystalline solids are anisotropic, meaning that the values of physical properties change with direction throughout the body of the solid.

There are two polymorphous structures of sulfur, rhombic and monoclinic. Polymorphous structures occur when a single substance can crystallize in two or more forms depending upon the conditions.

Molecular solids are solids that are collections of molecules held together by intermolecular forces. In polar molecules such as HCl, So2, etc., the molecules are held together by dipole-dipole interactions, which is the attraction between the positive and negative ends of the molecules.

A cubic crystal has three equal dimensions, a = b = c, and three angles, α = β = γ = 90. This is because a cubic crystal is a symmetrical structure, with each side of the cube being equal in length and each angle being equal in measure. The angles of a cube are all right angles, meaning that the measure of each angle is 90 degrees.

The face-centred cubic cell is a type of unit cell in which atoms are present at the corners and faces of the unit cell. In this type of unit cell, a unit cell is shared equally by six unit cells.

The unit cell in which the constituent atoms are present only at the corner is known as simple cubic cell. It is also referred to as a primitive cubic cell. In the simple cubic cell, each corner atom is shared by eight different unit cells.

Lattice points are the points at which atoms may be present on the unit cell. They indicate the position of atoms in a crystal.

Solids are classified as crystalline and amorphous solids based on their crystal structures. In crystalline solids, the constituent particles are arranged in a regular manner, while in amorphous solids, the constituent particles are not arranged in any regular manner.

Solid CO2 is an example of molecular crystal. These solids have molecules as their constituent particles. These solids may be bonded by vander waals’ forces or by dipole-dipole attraction or by strong hydrogen bonds. H2, Cl2, I2 are some examples of molecular solids.