Crystalline solids are isotropic.
State whether the given statement is true or false.

Hint: A solid is said to be isotropic if it has such an arrangement of the molecules in its crystal structure that all the physical properties do remain constant or uniform in all the principal directions of the crystal structure.

Complete answer: The solids can be classified into true types that are crystalline solids and amorphous solids. The crystalline solids have a regular and definite arrangement of repeating three- dimensional patterns of atoms, ions and molecules in a highly ordered microscopic structure to form a crystal lattice which extends in all the directions whereas the amorphous solids are formed by condensing the atoms on the cold surface and also the atoms and molecules are not organized in a definite lattice pattern.
There are four categories of crystalline solids that are molecular solids, network or covalent solids, ionic solids and the metallic solids. In all these types of crystalline solids, the atoms and molecules are held together by London dispersion, dipole – dipole or hydrogen bonds, the covalent solids are held by covalent bonds the ionic solids are held by ionic bonds and the metallic solids are held together by metallic bonds. But however the arrangement of molecules is the same in all these types of crystalline solids.
Due to the some regular arrangement of atoms and molecules in all directions the physical properties do change in the opposite direction. And we already know that the isotropic solids have the same physical properties in all the directions. Thus we can say that crystalline solids are not isotropic.
So, the statement is false.

Note:
The crystalline solids are anisotropic in nature, this means that the physical properties do change with the change in direction. On the other hand, amorphous amorphous solids are isotropic in nature.