Chapter 11, Problem 76RQ

Interpretation Introduction

Interpretation:

The terms lattice and unit cell are to be defined for a cell.

Concept Introduction:

Solids are the substances which have strong forces of attraction between their molecules. The atoms are tightly bound and cannot be compressed by pressure. These can be of two types: Amorphous and crystalline solids.

Amorphous solids are formed when the molecules of atom are tightly coupled together such that they are fixed in their position. These do not have any fixed shape. Such solids are glass, polymers and gels.

On the other hand, crystalline solids are defined as the type of solids in which the atoms or molecules occupy specific positions. These are rigid and compact in nature. These possess long range order and definite melting points. For example: sodium chloride, diamond etc..