Question

Which of the following are properties of crystalline solid?
A) Isotropic
B) Sharp melting point
C) Long Range order
D) Definite Regular Geometry

Answer 1

To solve this question, we must first understand some basic concepts and properties about Crystalline Solid. Then we need to assess the properties and one by one match them with the given options and select the correct ones and then only we can conclude the correct answer.

Complete step by step answer:
Before we move forward with the solution of this given question, let us first understand some basic concepts about Solids and Crystalline Solid:
Solid: is defined as a few atomic layers that separate two solids in intimate contact with one another, where the properties differ significantly from those of the bulk material it separates.
Based on their crystal structures, solids can be classified into the following categories:
a) Crystalline solids
b) Amorphous solids
Crystalline Solid: solids featuring highly ordered arrangements of their particles (atoms, ions, and molecules) in microscopic structures are called crystalline solids. These ordered microscopic structures make up a crystal lattice that accounts for the structure of the solid at any given point.
Properties of Crystalline Solids:

1. They have definite and regular geometry and have long range as well as short range order of constituent particles.
2. They tend to have relatively sharp, well-defined melting points because all the component atoms, molecules, or ions are the same distance from the same number and type of neighbours.
3. They have a long-range order which means that there is a regular pattern of arrangement of particles which repeats itself periodically over the entire crystal.
4. Give a clean surface after cleavage with a knife.
5. Have definite heat of fusion.
6. Are very rigid and their molecules cannot be deformed by mild distorting force.
7. Are considered as true solid.
8. They display anisotropism.
   So, clearly by going through the above stated properties, we can conclude that the correct answers are Option B, C and D.

Note: Seven crystal structures are available in total: triclinic, monoclinic, orthorhombic, tetragonal, trigonal, hexagonal, and cubic. A family of crystals is determined by groupings of lattices and lines.