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

Hint:This question gives the knowledge about crystalline solid and its properties. Crystalline solids are the solids whose atoms, ions or molecules possess definite regular geometry. Crystalline solids generally form crystal lattice which is extended in all the directions.

Complete answer:
Crystalline solids are the solids whose atoms, ions or molecules possess definite regular geometry. Crystalline solids generally form crystal lattices which are extended in all directions. Crystalline solids are also called true solids. Crystalline solids are of four types which are covalent solids, ionic solids, molecular solids and metallic solids. Examples of crystalline solids are diamond, sodium chloride and sodium nitrate. Along with these properties crystalline solids possess various other properties.
Other properties of crystalline solids are as follows:
$1$. Crystalline solids possess three dimensional patterns which leads to the formation of crystal lattice.
$2$. Crystalline solids are anisotropic in nature which means they possess different properties in different directions.
$3$. Crystalline solid possesses rigid structures.
$4$. Crystalline solid possesses perfect regular geometry.
$5$. Crystalline solids can be cleaved in two smooth surfaces.
$6$. Crystalline solids possess definite heat of fusion.
$7$. Their melting point is very high.
Crystalline solids are not isotropic in nature. Crystalline solids are anisotropic in nature which means they possess different properties in different directions. Crystalline solid possesses these properties such as sharp melting point, long range order and definite regular geometry.

Therefore, options $B$ , $C$ , $D$ are correct.

Note:
Always remember that crystalline solids are also called true solids whereas amorphous solids are called pseudo solids. Crystalline solids form crystal lattice due to its three-dimensional arrangement. Crystalline solids generally form crystal lattice which is extended in all the directions.