Which of the following is not a characteristic of a crystalline solid?
(i) Definite and characteristic heat of fusion.
(ii) Isotropic nature.
(iii) A regular periodically repeated pattern of arrangement of constituent particles in the entire crystal.
(iv) A true solid
The answer is the option (ii) Anisotropy: Crystalline solids are anisotropic in nature. In Anisotropic substances, physical properties like electrical resistance or refractive index show different values when measured along different directions in the same crystal. This is primarily due to different arrangement of particles in different directions arrangement of particles along different directions
Isotropy: In isotropic substances, physical properties like electrical conductivity, refractive index etc. show the same value when measured in different directions just like in glass or liquid. Amorphous substances exhibit Isotropy.