(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

Correct Answer: (ii) Isotropic nature

Explanation: Crystalline solids are naturally anisotropic, which is one of their physical properties such as electrical resistance or refractive index showing different values ​​when measured with different indicators in the same crystal. This arises from different particle arrangement.